diff --git a/docs/contrib/TclContract.md b/docs/contrib/TclContract.md
index 9ec7ab1623..067783b3a7 100644
--- a/docs/contrib/TclContract.md
+++ b/docs/contrib/TclContract.md
@@ -26,8 +26,8 @@ to follow.
 
 - **A script never writes its own version of an idiom `util.tcl` already
   has.** An optional flag is added with `append_env_var`, a command that does
-  real work runs through `log_cmd`, a result is written with `orfs_write_db`
-  and `orfs_write_sdc`. An idiom a change needs in two places becomes a proc
+  real work runs through `log_cmd`, a result is written with `orfs_write_db`,
+  which writes the `.odb` and its `.sdc`. An idiom a change needs in two places becomes a proc
   in `util.tcl`.
   *Breaks:* each copy grows its own small bug, and nobody can grep for the
   places that do the same thing.
diff --git a/flow/Makefile b/flow/Makefile
index 2ef5b3b645..79d28aedff 100644
--- a/flow/Makefile
+++ b/flow/Makefile
@@ -350,8 +350,7 @@ clean_synth:
 # |_|   |_____\___/ \___/|_| \_\_|   |_____/_/   \_\_| \_|
 #
 .PHONY: floorplan
-floorplan: $(RESULTS_DIR)/2_floorplan.odb \
-           $(RESULTS_DIR)/2_floorplan.sdc
+floorplan: $(RESULTS_DIR)/2_floorplan.odb
 
 # ==============================================================================
 
@@ -414,10 +413,11 @@ $(eval $(call OPEN_GUI_SHORTCUT,5_1_grt-failed,5_1_grt-failed.odb))
 # $(1) stem, e.g. 2_1_floorplan
 # $(2) dependencies
 # $(3) tcl script step
-# $(4) extension of result, default .odb
+# $(4) extension of result, default .odb; an .odb result comes with
+#     its .sdc, declared as one grouped target
 # $(5) folder of target, default $(RESULTS_DIR)
 define do-step
-$(if $(5),$(5),$(RESULTS_DIR))/$(1)$(if $(4),$(4),.odb): $(2)
+$(if $(filter-out .odb,$(4)),$(if $(5),$(5),$(RESULTS_DIR))/$(1)$(4):,$(RESULTS_DIR)/$(1).odb $(RESULTS_DIR)/$(1).sdc &:) $(2)
 	$$(UNSET_AND_MAKE) do-$(1)
 
 ifeq ($(if $(4),$(4),.odb),.odb)
@@ -432,33 +432,32 @@ do-$(1): $(DO_STEP_DEPS_$(1)) $(OBJECTS_DIR)/copyright.txt
 	$(SCRIPTS_DIR)/flow.sh $(1) $(3)
 endef
 
-# generate make rules to copy a file, if a dependency change and
-# a do- sibling rule that copies the file unconditionally.
+# generate make rules to copy an .odb and its .sdc, if a dependency
+# change and a do- sibling rule that copies them unconditionally.
 #
-# The file is copied within the $(RESULTS_DIR)
+# The files are copied within the $(RESULTS_DIR)
 #
-# $(1) stem of target, e.g. 2_1_floorplan
-# $(2) basename of file to be copied
-# $(3) further dependencies
-# $(4) target extension, default .odb
+# $(1) stem of target, e.g. 2_floorplan
+# $(2) stem of the files to be copied, e.g. 2_4_floorplan_pdn
 define do-copy
-$(RESULTS_DIR)/$(1)$(if $(4),$(4),.odb): $(RESULTS_DIR)/$(2) $(3)
-	$$(UNSET_AND_MAKE) do-$(1)$(if $(4),$(4),)
+$(RESULTS_DIR)/$(1).odb $(RESULTS_DIR)/$(1).sdc &: $(RESULTS_DIR)/$(2).odb
+	$$(UNSET_AND_MAKE) do-$(1)
 
-.PHONY: do-$(1)$(if $(4),$(4),)
-do-$(1)$(if $(4),$(4),):
-	cp $(RESULTS_DIR)/$(2) $(RESULTS_DIR)/$(1)$(if $(4),$(4),.odb)
+.PHONY: do-$(1)
+do-$(1):
+	cp $(RESULTS_DIR)/$(2).sdc $(RESULTS_DIR)/$(1).sdc
+	cp $(RESULTS_DIR)/$(2).odb $(RESULTS_DIR)/$(1).odb
 endef
 
 # ==============================================================================
 
 # Custom target to go from synthesis to placement in a single OpenROAD run
-$(eval $(call do-step,1_3_floorplan_to_place, $(RESULTS_DIR)/1_synth.odb $(RESULTS_DIR)/1_synth.sdc,floorplan_to_place))
+$(eval $(call do-step,1_3_floorplan_to_place, $(RESULTS_DIR)/1_synth.odb,floorplan_to_place))
 
 $(eval $(call OPEN_GUI_SHORTCUT,yosys,1_2_yosys.v))
 
 .PHONY: floorplan_to_place
-floorplan_to_place: $(RESULTS_DIR)/1_synth.odb $(RESULTS_DIR)/1_synth.sdc
+floorplan_to_place: $(RESULTS_DIR)/1_synth.odb
 	$(UNSET_AND_MAKE) do-1_3_floorplan_to_place
 
 # ==============================================================================
@@ -469,8 +468,6 @@ else
 $(eval $(call do-step,1_synth,$(RESULTS_DIR)/1_2_yosys.v $(RESULTS_DIR)/1_2_yosys.sdc $(TECH_LEF) $(SC_LEF) $(ADDITIONAL_LEFS) $(LIB_FILES),synth_odb))
 endif
 
-$(RESULTS_DIR)/1_synth.sdc: $(RESULTS_DIR)/1_synth.odb
-
 FORMAL_CHECK_DEPS =
 ifneq ($(filter 1,$(LEC_CHECK) $(SEC_CHECK)),)
 FORMAL_CHECK_DEPS += $(RESULTS_DIR)/1_synth_lec.v
@@ -484,20 +481,18 @@ check-kepler-formal:
 		exit 1; \
 	fi
 
-$(RESULTS_DIR)/1_synth_lec.v: $(RESULTS_DIR)/1_synth.odb $(RESULTS_DIR)/1_synth.sdc
+$(RESULTS_DIR)/1_synth_lec.v: $(RESULTS_DIR)/1_synth.odb
 	$(UNSET_AND_MAKE) do-1_synth
 
 ifneq ($(filter 1,$(LEC_CHECK) $(SEC_CHECK)),)
 $(RESULTS_DIR)/1_synth_lec.v: | check-kepler-formal
 endif
 
-$(eval $(call do-step,2_1_floorplan,$(RESULTS_DIR)/1_synth.odb $(RESULTS_DIR)/1_synth.sdc $(TECH_LEF) $(SC_LEF) $(ADDITIONAL_LEFS) $(FOOTPRINT) $(SIG_MAP_FILE) $(FOOTPRINT_TCL) $(LIB_FILES) $(IO_CONSTRAINTS),floorplan))
-
-$(eval $(call do-copy,2_floorplan,2_1_floorplan.sdc,,.sdc))
+$(eval $(call do-step,2_1_floorplan,$(RESULTS_DIR)/1_synth.odb $(TECH_LEF) $(SC_LEF) $(ADDITIONAL_LEFS) $(FOOTPRINT) $(SIG_MAP_FILE) $(FOOTPRINT_TCL) $(LIB_FILES) $(IO_CONSTRAINTS),floorplan))
 
 # STEP 2: Macro Placement
 #-------------------------------------------------------------------------------
-$(eval $(call do-step,2_2_floorplan_macro,$(RESULTS_DIR)/2_1_floorplan.odb $(RESULTS_DIR)/1_synth.sdc $(MACRO_PLACEMENT) $(MACRO_PLACEMENT_TCL),macro_place))
+$(eval $(call do-step,2_2_floorplan_macro,$(RESULTS_DIR)/2_1_floorplan.odb $(MACRO_PLACEMENT) $(MACRO_PLACEMENT_TCL),macro_place))
 
 # STEP 3: Tapcell and Welltie insertion
 #-------------------------------------------------------------------------------
@@ -507,17 +502,15 @@ $(eval $(call do-step,2_3_floorplan_tapcell,$(RESULTS_DIR)/2_2_floorplan_macro.o
 #-------------------------------------------------------------------------------
 $(eval $(call do-step,2_4_floorplan_pdn,$(RESULTS_DIR)/2_3_floorplan_tapcell.odb $(PDN_TCL),pdn))
 
-$(eval $(call do-copy,2_floorplan,2_4_floorplan_pdn.odb,))
-
-$(RESULTS_DIR)/2_floorplan.sdc: $(RESULTS_DIR)/2_1_floorplan.odb
+$(eval $(call do-copy,2_floorplan,2_4_floorplan_pdn))
 
 .PHONY: do-floorplan
 do-floorplan:
-	$(UNSET_AND_MAKE) do-2_1_floorplan do-2_2_floorplan_macro do-2_3_floorplan_tapcell do-2_4_floorplan_pdn do-2_floorplan do-2_floorplan.sdc
+	$(UNSET_AND_MAKE) do-2_1_floorplan do-2_2_floorplan_macro do-2_3_floorplan_tapcell do-2_4_floorplan_pdn do-2_floorplan
 
 .PHONY: clean_floorplan
 clean_floorplan:
-	rm -f $(RESULTS_DIR)/2_*floorplan*.odb $(RESULTS_DIR)/2_floorplan.sdc $(RESULTS_DIR)/2_*.v $(RESULTS_DIR)/2_*.def
+	rm -f $(RESULTS_DIR)/2_*floorplan*.odb $(RESULTS_DIR)/2_*floorplan*.sdc $(RESULTS_DIR)/2_*.v $(RESULTS_DIR)/2_*.def
 	rm -f $(REPORTS_DIR)/2_*
 	rm -f $(LOG_DIR)/2_*
 
@@ -529,22 +522,21 @@ clean_floorplan:
 # |_|   |_____/_/   \_\____|_____|
 #
 .PHONY: place
-place: $(RESULTS_DIR)/3_place.odb \
-       $(RESULTS_DIR)/3_place.sdc
+place: $(RESULTS_DIR)/3_place.odb
 # ==============================================================================
 # STEP 1: Global placement without placed IOs, timing-driven, and routability-driven.
 #-------------------------------------------------------------------------------
-$(eval $(call do-step,3_1_place_gp_skip_io,$(RESULTS_DIR)/2_floorplan.odb $(RESULTS_DIR)/2_floorplan.sdc $(LIB_FILES),global_place_skip_io))
+$(eval $(call do-step,3_1_place_gp_skip_io,$(RESULTS_DIR)/2_floorplan.odb $(LIB_FILES),global_place_skip_io))
 
 $(eval $(call do-step,3_2_place_iop,$(RESULTS_DIR)/3_1_place_gp_skip_io.odb,io_placement))
 
 # STEP 3: Global placement with placed IOs, timing-driven, and routability-driven.
 #-------------------------------------------------------------------------------
-$(eval $(call do-step,3_3_place_gp,$(RESULTS_DIR)/3_2_place_iop.odb $(RESULTS_DIR)/2_floorplan.sdc $(LIB_FILES),global_place))
+$(eval $(call do-step,3_3_place_gp,$(RESULTS_DIR)/3_2_place_iop.odb $(LIB_FILES),global_place))
 
 # STEP 4: Resizing & Buffering
 #-------------------------------------------------------------------------------
-$(eval $(call do-step,3_4_place_resized,$(RESULTS_DIR)/3_3_place_gp.odb $(RESULTS_DIR)/2_floorplan.sdc,resize))
+$(eval $(call do-step,3_4_place_resized,$(RESULTS_DIR)/3_3_place_gp.odb,resize))
 
 .PHONY: clean_resize
 clean_resize:
@@ -554,11 +546,7 @@ clean_resize:
 #-------------------------------------------------------------------------------
 $(eval $(call do-step,3_5_place_dp,$(RESULTS_DIR)/3_4_place_resized.odb,detail_place))
 
-$(eval $(call do-copy,3_place,3_5_place_dp.odb,))
-
-# detail_place writes 3_place.sdc alongside 3_5_place_dp.odb (constraints
-# are unchanged during placement), mirroring how synth writes 1_synth.sdc.
-$(RESULTS_DIR)/3_place.sdc: $(RESULTS_DIR)/3_5_place_dp.odb
+$(eval $(call do-copy,3_place,3_5_place_dp))
 
 .PHONY: do-place
 do-place:
@@ -569,7 +557,7 @@ do-place:
 .PHONY: clean_place
 clean_place:
 	rm -f $(RESULTS_DIR)/3_*place*.odb
-	rm -f $(RESULTS_DIR)/3_place.sdc
+	rm -f $(RESULTS_DIR)/3_*place*.sdc
 	rm -f $(RESULTS_DIR)/3_*.def $(RESULTS_DIR)/3_*.v
 	rm -f $(REPORTS_DIR)/3_*
 	rm -f $(LOG_DIR)/3_*
@@ -583,8 +571,7 @@ clean_place:
 #  \____| |_| |____/
 #
 .PHONY: cts
-cts: $(RESULTS_DIR)/4_cts.odb \
-     $(RESULTS_DIR)/4_cts.sdc
+cts: $(RESULTS_DIR)/4_cts.odb
 # ==============================================================================
 
 # Run TritonCTS
@@ -593,15 +580,13 @@ ifeq ($(LEC_CHECK),1)
 DO_STEP_DEPS_4_1_cts += check-kepler-formal
 endif
 
-$(eval $(call do-step,4_1_cts,$(RESULTS_DIR)/3_place.odb $(RESULTS_DIR)/3_place.sdc,cts))
+$(eval $(call do-step,4_1_cts,$(RESULTS_DIR)/3_place.odb,cts))
 
 ifeq ($(LEC_CHECK),1)
 $(RESULTS_DIR)/4_1_cts.odb: | check-kepler-formal
 endif
 
-$(RESULTS_DIR)/4_cts.sdc: $(RESULTS_DIR)/4_cts.odb
-
-$(eval $(call do-copy,4_cts,4_1_cts.odb))
+$(eval $(call do-copy,4_cts,4_1_cts))
 
 .PHONY: do-cts
 do-cts:
@@ -609,7 +594,7 @@ do-cts:
 
 .PHONY: clean_cts
 clean_cts:
-	rm -rf $(RESULTS_DIR)/4_*cts*.odb $(RESULTS_DIR)/4_cts.sdc $(RESULTS_DIR)/4_*.v $(RESULTS_DIR)/4_*.def
+	rm -rf $(RESULTS_DIR)/4_*cts*.odb $(RESULTS_DIR)/4_*cts*.sdc $(RESULTS_DIR)/4_*.v $(RESULTS_DIR)/4_*.def
 	rm -f  $(REPORTS_DIR)/4_*
 	rm -rf $(LOG_DIR)/4_*
 
@@ -622,8 +607,7 @@ clean_cts:
 # |_| \_\\___/ \___/  |_| |___|_| \_|\____|
 #
 .PHONY: route
-route: $(RESULTS_DIR)/5_route.odb \
-       $(RESULTS_DIR)/5_route.sdc
+route: $(RESULTS_DIR)/5_route.odb
 
 .PHONY: grt globalroute
 globalroute: grt
@@ -642,13 +626,11 @@ $(eval $(call do-step,5_2_route,$(RESULTS_DIR)/5_1_grt.odb,detail_route))
 
 $(eval $(call do-step,5_3_fillcell,$(RESULTS_DIR)/5_2_route.odb,fillcell))
 
-$(eval $(call do-copy,5_route,5_3_fillcell.odb))
-
-$(eval $(call do-copy,5_route,5_1_grt.sdc,,.sdc))
+$(eval $(call do-copy,5_route,5_3_fillcell))
 
 .PHONY: do-route
 do-route:
-	$(UNSET_AND_MAKE) do-5_1_grt do-5_2_route do-5_3_fillcell do-5_route do-5_route.sdc
+	$(UNSET_AND_MAKE) do-5_1_grt do-5_2_route do-5_3_fillcell do-5_route
 
 .PHONY: do-grt
 do-grt:
@@ -657,7 +639,7 @@ do-grt:
 .PHONY: clean_route
 clean_route:
 	rm -rf $(RESULTS_DIR)/route.guide $(RESULTS_DIR)/output_guide.mod $(RESULTS_DIR)/updated_clks.sdc
-	rm -rf $(RESULTS_DIR)/5_*.odb $(RESULTS_DIR)/5_route.sdc $(RESULTS_DIR)/5_*.def $(RESULTS_DIR)/5_*.v
+	rm -rf $(RESULTS_DIR)/5_*.odb $(RESULTS_DIR)/5_*.sdc $(RESULTS_DIR)/5_*.def $(RESULTS_DIR)/5_*.v
 	rm -f  $(REPORTS_DIR)/5_*
 	rm -f  $(LOG_DIR)/5_*
 
@@ -686,7 +668,6 @@ klayout_guides: $(RESULTS_DIR)/5_route.def $(OBJECTS_DIR)/klayout.lyt
 .PHONY: finish
 finish: $(LOG_DIR)/6_report.log \
         $(RESULTS_DIR)/6_final.v \
-        $(RESULTS_DIR)/6_final.sdc \
         $(GDS_FINAL_FILE)
 	$(UNSET_AND_MAKE) elapsed
 
@@ -699,25 +680,20 @@ elapsed:
 elapsed-all:
 	@$(PYTHON_EXE) $(UTILS_DIR)/genElapsedTime.py -d $(shell find $(WORK_HOME)/logs/$(PLATFORM)/*/*/ -type d)
 
-$(eval $(call do-step,6_1_fill,$(RESULTS_DIR)/5_route.odb $(RESULTS_DIR)/5_route.sdc $(FILL_CONFIG),density_fill))
-
-$(eval $(call do-copy,6_1_fill,5_route.sdc,,.sdc))
+$(eval $(call do-step,6_1_fill,$(RESULTS_DIR)/5_route.odb $(FILL_CONFIG),density_fill))
 
 ifneq ($(filter 1,$(LEC_CHECK) $(SEC_CHECK)),)
 DO_STEP_DEPS_6_report += check-kepler-formal
 endif
 
-$(eval $(call do-step,6_report,$(RESULTS_DIR)/6_1_fill.odb $(RESULTS_DIR)/6_1_fill.sdc $(FORMAL_CHECK_DEPS),final_report,.log,$(LOG_DIR)))
+$(eval $(call do-step,6_report,$(RESULTS_DIR)/6_1_fill.odb $(FORMAL_CHECK_DEPS),final_report,.log,$(LOG_DIR)))
 
 ifneq ($(filter 1,$(LEC_CHECK) $(SEC_CHECK)),)
 $(LOG_DIR)/6_report.log: | check-kepler-formal
 endif
 
-# final_report writes 6_final.sdc alongside 6_final.odb (constraints are
-# unchanged during finishing), mirroring how synth writes 1_synth.sdc.
-$(RESULTS_DIR)/6_final.sdc: $(LOG_DIR)/6_report.log
-
 $(RESULTS_DIR)/6_final.def: $(LOG_DIR)/6_report.log
+$(RESULTS_DIR)/6_final.odb $(RESULTS_DIR)/6_final.sdc: $(LOG_DIR)/6_report.log
 
 # Written only when final extracts parasitics (RCX_RULES set, detailed
 # route not skipped); generate_abstract reads it in that case.
@@ -733,7 +709,7 @@ final: finish
 
 .PHONY: do-finish
 do-finish:
-	$(UNSET_AND_MAKE) do-6_1_fill do-6_1_fill.sdc do-6_report elapsed
+	$(UNSET_AND_MAKE) do-6_1_fill do-6_report elapsed
 
 .PHONY: generate_abstract
 generate_abstract: $(RESULTS_DIR)/6_final.gds $(RESULTS_DIR)/6_final.def  $(RESULTS_DIR)/6_final.v $(RESULTS_DIR)/6_final.sdc $(RESULTS_DIR)/6_final.spef
diff --git a/flow/scripts/cdl.tcl b/flow/scripts/cdl.tcl
index f45d941ef4..e5f5ca3f59 100644
--- a/flow/scripts/cdl.tcl
+++ b/flow/scripts/cdl.tcl
@@ -1,5 +1,5 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables final
-load_design 6_final.odb 6_final.sdc
+load_design 6_final.odb
 
 write_cdl -masters $::env(CDL_FILE) $::env(RESULTS_DIR)/6_final.cdl
diff --git a/flow/scripts/cts.tcl b/flow/scripts/cts.tcl
index 7439569d12..fdb9d54ada 100644
--- a/flow/scripts/cts.tcl
+++ b/flow/scripts/cts.tcl
@@ -2,7 +2,7 @@ utl::set_metrics_stage "cts__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 source $::env(SCRIPTS_DIR)/formal_check.tcl
 erase_non_stage_variables cts
-load_design 3_place.odb 3_place.sdc
+load_design 3_place.odb
 source_step_tcl PRE CTS
 
 # Clone clock tree inverters next to register loads
@@ -12,7 +12,6 @@ repair_clock_inverters
 proc save_progress { stage } {
   puts "Run 'make gui_$stage.odb' to load progress snapshot"
   orfs_write_db $::env(RESULTS_DIR)/$stage.odb
-  orfs_write_sdc $::env(RESULTS_DIR)/$stage.sdc
 }
 
 # Run CTS
@@ -87,4 +86,3 @@ report_metrics 4 "cts final"
 source_step_tcl POST CTS
 
 orfs_write_db $::env(RESULTS_DIR)/4_1_cts.odb
-orfs_write_sdc $::env(RESULTS_DIR)/4_cts.sdc
diff --git a/flow/scripts/density_fill.tcl b/flow/scripts/density_fill.tcl
index 1f93ed4c52..030c2c3825 100644
--- a/flow/scripts/density_fill.tcl
+++ b/flow/scripts/density_fill.tcl
@@ -1,6 +1,6 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables final
-load_design 5_route.odb 5_route.sdc
+load_design 5_route.odb
 source_step_tcl PRE DENSITY_FILL
 
 if { $::env(USE_FILL) } {
diff --git a/flow/scripts/detail_place.tcl b/flow/scripts/detail_place.tcl
index 6a4216f717..643a7b3930 100644
--- a/flow/scripts/detail_place.tcl
+++ b/flow/scripts/detail_place.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "detailedplace__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables place
-load_design 3_4_place_resized.odb 2_floorplan.sdc
+load_design 3_4_place_resized.odb
 source_step_tcl PRE DETAIL_PLACE
 
 proc do_dpl { } {
@@ -40,4 +40,3 @@ report_metrics 3 "detailed place" true false
 source_step_tcl POST DETAIL_PLACE
 
 orfs_write_db $::env(RESULTS_DIR)/3_5_place_dp.odb
-orfs_write_sdc $::env(RESULTS_DIR)/3_place.sdc
diff --git a/flow/scripts/detail_route.tcl b/flow/scripts/detail_route.tcl
index 4bdc0c10f4..40b96eecb6 100644
--- a/flow/scripts/detail_route.tcl
+++ b/flow/scripts/detail_route.tcl
@@ -1,6 +1,6 @@
 utl::set_metrics_stage "detailedroute__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
-load_design 5_1_grt.odb 5_1_grt.sdc
+load_design 5_1_grt.odb
 source_step_tcl PRE DETAIL_ROUTE
 
 if { !$::env(SKIP_DETAILED_ROUTE) } {
diff --git a/flow/scripts/fillcell.tcl b/flow/scripts/fillcell.tcl
index 032c1ab58b..f88417db9a 100644
--- a/flow/scripts/fillcell.tcl
+++ b/flow/scripts/fillcell.tcl
@@ -1,7 +1,7 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables route
 if { [env_var_exists_and_non_empty FILL_CELLS] } {
-  load_design 5_2_route.odb 5_1_grt.sdc
+  load_design 5_2_route.odb
   source_step_tcl PRE FILLCELL
 
   set_propagated_clock [all_clocks]
diff --git a/flow/scripts/final_connect.tcl b/flow/scripts/final_connect.tcl
index 22324613c6..df059d73b5 100644
--- a/flow/scripts/final_connect.tcl
+++ b/flow/scripts/final_connect.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "finish__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables final
-load_design 6_1_fill.odb 6_1_fill.sdc
+load_design 6_1_fill.odb
 source_step_tcl PRE FINAL_REPORT
 
 set_propagated_clock [all_clocks]
diff --git a/flow/scripts/final_report.tcl b/flow/scripts/final_report.tcl
index 2916f2f473..54a2e3ebda 100644
--- a/flow/scripts/final_report.tcl
+++ b/flow/scripts/final_report.tcl
@@ -4,5 +4,4 @@
 source $::env(SCRIPTS_DIR)/final_connect.tcl
 # final_outputs.tcl writes the endpoint slack after parasitic extraction
 orfs_write_db $::env(RESULTS_DIR)/6_final.odb 0
-orfs_write_sdc $::env(RESULTS_DIR)/6_final.sdc
 source $::env(SCRIPTS_DIR)/final_outputs.tcl
diff --git a/flow/scripts/floorplan.tcl b/flow/scripts/floorplan.tcl
index 3190eeb612..26dea568b0 100644
--- a/flow/scripts/floorplan.tcl
+++ b/flow/scripts/floorplan.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "floorplan__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables floorplan
-load_design 1_synth.odb 1_synth.sdc
+load_design 1_synth.odb
 
 # The global connections, before any step can mark an instance
 # dont_touch: global_connect skips one (ODB-0383). The rules stay in the
@@ -175,4 +175,3 @@ source_step_tcl POST FLOORPLAN
 source_env_var_if_exists IO_CONSTRAINTS
 
 orfs_write_db $::env(RESULTS_DIR)/2_1_floorplan.odb
-orfs_write_sdc $::env(RESULTS_DIR)/2_1_floorplan.sdc
diff --git a/flow/scripts/flow.tcl b/flow/scripts/flow.tcl
index cd7f0a26bd..a89766a943 100644
--- a/flow/scripts/flow.tcl
+++ b/flow/scripts/flow.tcl
@@ -2,12 +2,12 @@
 # the final report, in a single OpenROAD process.
 #
 # With WRITE_ODB_AND_SDC_EACH_STAGE=0 the per-stage orfs_write_db /
-# orfs_write_sdc / orfs_copy_db helpers are no-ops, so this top level is
-# the sole writer of .odb/.sdc files. flow_write_db/flow_write_sdc
-# produce the same file set as the stage-per-process make flow (the
-# extra writes after a stage's own mirror the Makefile do-copy
-# recipes), and flow_source enforces that stage scripts write no
-# .odb/.sdc files themselves.
+# orfs_copy_db helpers are no-ops, so this top level is the sole writer
+# of .odb/.sdc files. flow_write_db writes each .odb with its .sdc,
+# the same file set as the stage-per-process make flow (the extra
+# writes after a stage's own mirror the Makefile do-copy recipes), and
+# flow_source enforces that stage scripts write no .odb/.sdc files
+# themselves.
 
 # Enable keeping variables between stages
 set ::env(KEEP_VARS) 1
@@ -30,25 +30,19 @@ proc flow_source { script } {
 
 proc flow_write_db { name } {
   set path [file join $::env(RESULTS_DIR) $name]
+  set sdc [sdc_file_of $path]
+  log_cmd write_sdc -no_timestamp $sdc
   log_cmd write_db $path
-  lappend ::flow_expected $path
-}
-
-proc flow_write_sdc { name } {
-  set path [file join $::env(RESULTS_DIR) $name]
-  log_cmd write_sdc -no_timestamp $path
-  lappend ::flow_expected $path
+  lappend ::flow_expected $path $sdc
 }
 
 # Synthesis odb (from the yosys netlist)
 flow_source synth_odb.tcl
 flow_write_db 1_synth.odb
-flow_write_sdc 1_synth.sdc
 
 # Floorplan
 flow_source floorplan.tcl
 flow_write_db 2_1_floorplan.odb
-flow_write_sdc 2_1_floorplan.sdc
 flow_source macro_place.tcl
 flow_write_db 2_2_floorplan_macro.odb
 flow_source tapcell.tcl
@@ -56,7 +50,6 @@ flow_write_db 2_3_floorplan_tapcell.odb
 flow_source pdn.tcl
 flow_write_db 2_4_floorplan_pdn.odb
 flow_write_db 2_floorplan.odb
-flow_write_sdc 2_floorplan.sdc
 
 # Place
 flow_source global_place_skip_io.tcl
@@ -70,31 +63,25 @@ flow_write_db 3_4_place_resized.odb
 flow_source detail_place.tcl
 flow_write_db 3_5_place_dp.odb
 flow_write_db 3_place.odb
-flow_write_sdc 3_place.sdc
 
 # CTS
 flow_source cts.tcl
 flow_write_db 4_1_cts.odb
 flow_write_db 4_cts.odb
-flow_write_sdc 4_cts.sdc
 
 # Route
 flow_source global_route.tcl
 flow_write_db 5_1_grt.odb
-flow_write_sdc 5_1_grt.sdc
 flow_source detail_route.tcl
 flow_write_db 5_2_route.odb
 flow_source fillcell.tcl
 flow_write_db 5_3_fillcell.odb
 flow_write_db 5_route.odb
-flow_write_sdc 5_route.sdc
 
 # Finish. final_report.tcl is split around its 6_final.odb write so
 # this top level can write at the same point.
 flow_source density_fill.tcl
 flow_write_db 6_1_fill.odb
-flow_write_sdc 6_1_fill.sdc
 flow_source final_connect.tcl
 flow_write_db 6_final.odb
-flow_write_sdc 6_final.sdc
 flow_source final_outputs.tcl
diff --git a/flow/scripts/generate_abstract.tcl b/flow/scripts/generate_abstract.tcl
index 733a2df7e1..7fc2fd9726 100644
--- a/flow/scripts/generate_abstract.tcl
+++ b/flow/scripts/generate_abstract.tcl
@@ -7,11 +7,9 @@ set stem [expr {
   "6_final"
 }]
 
-set result [find_sdc_file $stem.odb]
-set design_stage [lindex $result 0]
-set sdc_file [lindex $result 1]
+set design_stage [lindex [extract_stage $stem.odb] 0]
 
-log_cmd load_design $stem.odb [file tail $sdc_file]
+log_cmd load_design $stem.odb
 
 orfs_load_parasitics $stem
 
diff --git a/flow/scripts/global_place.tcl b/flow/scripts/global_place.tcl
index 4a125954e2..fce5809f23 100644
--- a/flow/scripts/global_place.tcl
+++ b/flow/scripts/global_place.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "globalplace__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables place
-load_design 3_2_place_iop.odb 2_floorplan.sdc
+load_design 3_2_place_iop.odb
 source_step_tcl PRE GLOBAL_PLACE
 
 set_dont_use $::env(DONT_USE_CELLS)
diff --git a/flow/scripts/global_place_skip_io.tcl b/flow/scripts/global_place_skip_io.tcl
index 96195d486e..aadaa5f014 100644
--- a/flow/scripts/global_place_skip_io.tcl
+++ b/flow/scripts/global_place_skip_io.tcl
@@ -5,7 +5,7 @@ if { $::env(GPL_PLACE_IOS) } {
     $::env(RESULTS_DIR)/3_1_place_gp_skip_io.odb
   return
 }
-load_design 2_floorplan.odb 2_floorplan.sdc
+load_design 2_floorplan.odb
 source_step_tcl PRE GLOBAL_PLACE_SKIP_IO
 
 if { [env_var_exists_and_non_empty FLOORPLAN_DEF] } {
diff --git a/flow/scripts/global_route.tcl b/flow/scripts/global_route.tcl
index 01ad91ba30..93213b19a5 100644
--- a/flow/scripts/global_route.tcl
+++ b/flow/scripts/global_route.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "globalroute__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables grt
-load_design 4_cts.odb 4_cts.sdc
+load_design 4_cts.odb
 
 source_step_tcl PRE GLOBAL_ROUTE
 
@@ -30,6 +30,7 @@ proc set_grt_seed { } {
 proc run_global_route_and_catch_failures { args } {
   if { [catch { log_cmd global_route {*}$args } errMsg] } {
     log_cmd write_db $::env(RESULTS_DIR)/5_1_grt-failed.odb
+    log_cmd write_sdc -no_timestamp $::env(RESULTS_DIR)/5_1_grt-failed.sdc
     error $errMsg
   }
 }
@@ -157,4 +158,3 @@ source [file join $::env(SCRIPTS_DIR) "write_ref_sdc.tcl"]
 write_guides $::env(RESULTS_DIR)/route.guide
 source_step_tcl POST GLOBAL_ROUTE
 orfs_write_db $::env(RESULTS_DIR)/5_1_grt.odb
-orfs_write_sdc $::env(RESULTS_DIR)/5_1_grt.sdc
diff --git a/flow/scripts/io_placement.tcl b/flow/scripts/io_placement.tcl
index ad4d7809e2..2db2d8addd 100644
--- a/flow/scripts/io_placement.tcl
+++ b/flow/scripts/io_placement.tcl
@@ -2,7 +2,7 @@ source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables place
 
 if { !$::env(GPL_PLACE_IOS) && ![pins_fixed_in_floorplan] } {
-  load_design 3_1_place_gp_skip_io.odb 2_floorplan.sdc
+  load_design 3_1_place_gp_skip_io.odb
   source_step_tcl PRE IO_PLACEMENT
   log_cmd place_pins \
     -hor_layers $::env(IO_PLACER_H) \
diff --git a/flow/scripts/load.tcl b/flow/scripts/load.tcl
index 7d70b67769..45f24bdff1 100644
--- a/flow/scripts/load.tcl
+++ b/flow/scripts/load.tcl
@@ -2,7 +2,7 @@ source $::env(SCRIPTS_DIR)/util.tcl
 
 source $::env(SCRIPTS_DIR)/report_metrics.tcl
 
-proc load_design { design_file sdc_file } {
+proc load_design { design_file } {
   # Do not reload if design is already loaded
   set db [ord::get_db]
   if { [$db getChip] != "NULL" && [[$db getChip] getBlock] != "NULL" } {
@@ -38,8 +38,7 @@ proc load_design { design_file sdc_file } {
     error "Unrecognized input file $design_file"
   }
 
-  # Read SDC file
-  log_cmd read_sdc $::env(RESULTS_DIR)/$sdc_file
+  log_cmd read_sdc $::env(RESULTS_DIR)/[sdc_file_of $design_file]
 
   if { [file exists $::env(PLATFORM_DIR)/derate.tcl] } {
     log_cmd source $::env(PLATFORM_DIR)/derate.tcl
diff --git a/flow/scripts/macro_place.tcl b/flow/scripts/macro_place.tcl
index 556cc30ccc..3541d50ef5 100644
--- a/flow/scripts/macro_place.tcl
+++ b/flow/scripts/macro_place.tcl
@@ -1,6 +1,6 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables floorplan
-load_design 2_1_floorplan.odb 2_1_floorplan.sdc
+load_design 2_1_floorplan.odb
 source_step_tcl PRE MACRO_PLACE
 
 # A register file in `mode netlist` dissolves onto the parent's rows
diff --git a/flow/scripts/open.tcl b/flow/scripts/open.tcl
index dc490e790e..e043c46850 100644
--- a/flow/scripts/open.tcl
+++ b/flow/scripts/open.tcl
@@ -33,14 +33,8 @@ if { [env_var_exists_and_non_empty DEF_FILE] } {
 }
 
 proc read_timing { input_file } {
-  set result [find_sdc_file $input_file]
-  set design_stage [lindex $result 0]
-  set sdc_file [lindex $result 1]
-
-  if { $sdc_file == "" } {
-    set sdc_file $::env(SDC_FILE)
-  }
-  log_cmd read_sdc $sdc_file
+  set design_stage [lindex [extract_stage $input_file] 0]
+  log_cmd read_sdc [sdc_file_of $input_file]
   if { [file exists $::env(PLATFORM_DIR)/derate.tcl] } {
     source $::env(PLATFORM_DIR)/derate.tcl
   }
diff --git a/flow/scripts/pdn.tcl b/flow/scripts/pdn.tcl
index 7a7c32b25f..05bbcb6610 100644
--- a/flow/scripts/pdn.tcl
+++ b/flow/scripts/pdn.tcl
@@ -1,6 +1,6 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables floorplan
-load_design 2_3_floorplan_tapcell.odb 2_1_floorplan.sdc
+load_design 2_3_floorplan_tapcell.odb
 source_step_tcl PRE PDN
 
 source $::env(PDN_TCL)
diff --git a/flow/scripts/resize.tcl b/flow/scripts/resize.tcl
index fa8a26da3d..1cfd01b08b 100644
--- a/flow/scripts/resize.tcl
+++ b/flow/scripts/resize.tcl
@@ -1,7 +1,7 @@
 utl::set_metrics_stage "placeopt__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables place
-load_design 3_3_place_gp.odb 2_floorplan.sdc
+load_design 3_3_place_gp.odb
 source_step_tcl PRE RESIZE
 
 log_cmd estimate_parasitics
diff --git a/flow/scripts/synth_metrics.tcl b/flow/scripts/synth_metrics.tcl
index d2fe0ab500..59c06f6d59 100644
--- a/flow/scripts/synth_metrics.tcl
+++ b/flow/scripts/synth_metrics.tcl
@@ -1,5 +1,5 @@
 utl::set_metrics_stage "synth__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
-load_design 1_2_yosys.v 1_synth.sdc
+load_design 1_2_yosys.v
 
 report_metrics 1 "Post synthesis" false false
diff --git a/flow/scripts/synth_odb.tcl b/flow/scripts/synth_odb.tcl
index 3c2ae23606..0f8585cef3 100644
--- a/flow/scripts/synth_odb.tcl
+++ b/flow/scripts/synth_odb.tcl
@@ -2,7 +2,7 @@ utl::set_metrics_stage "synth__{}"
 source $::env(SCRIPTS_DIR)/load.tcl
 source $::env(SCRIPTS_DIR)/formal_check.tcl
 erase_non_stage_variables synth
-load_design 1_2_yosys.v 1_2_yosys.sdc
+load_design 1_2_yosys.v
 source_step_tcl PRE SYNTH
 
 # Eliminate dead logic before writing the synthesis odb so that
@@ -29,13 +29,11 @@ report_design_area
 report_design_area_metrics
 
 source_step_tcl POST SYNTH
-orfs_write_db $::env(RESULTS_DIR)/1_synth.odb
-# Canonicalize 1_synth.sdc. The original SDC_FILE provided by
+# Also canonicalizes 1_synth.sdc. The original SDC_FILE provided by
 # the user could have dependencies, such as sourcing util.tcl,
 # which are read in here and a canonicalized version is written
-# out by OpenSTA that has no dependencies. Sole writer of
-# 1_synth.sdc.
-orfs_write_sdc $::env(RESULTS_DIR)/1_synth.sdc
+# out by OpenSTA that has no dependencies.
+orfs_write_db $::env(RESULTS_DIR)/1_synth.odb
 if { $::env(LEC_CHECK) || $::env(SEC_CHECK) } {
   write_lec_verilog 1_synth_lec.v
 }
diff --git a/flow/scripts/synth_syn.tcl b/flow/scripts/synth_syn.tcl
index 52617bd5ae..16a1445072 100644
--- a/flow/scripts/synth_syn.tcl
+++ b/flow/scripts/synth_syn.tcl
@@ -70,13 +70,11 @@ log_cmd repair_design -pre_placement
 
 report_metrics 1 "synth" false false
 
-orfs_write_db $::env(RESULTS_DIR)/1_synth.odb
-# Canonicalize 1_synth.sdc. The original SDC_FILE provided by
+# Also canonicalizes 1_synth.sdc. The original SDC_FILE provided by
 # the user could have dependencies, such as sourcing util.tcl,
 # which are read in here and a canonicalized version is written
-# out by OpenSTA that has no dependencies. Sole writer of
-# 1_synth.sdc.
-orfs_write_sdc $::env(RESULTS_DIR)/1_synth.sdc
+# out by OpenSTA that has no dependencies.
+orfs_write_db $::env(RESULTS_DIR)/1_synth.odb
 
 # Gate-level netlist for downstream consumers. The Bazel synthesis action
 # declares this file as an output, so it must be written unconditionally.
diff --git a/flow/scripts/tapcell.tcl b/flow/scripts/tapcell.tcl
index 94620cbef8..95de249fd2 100644
--- a/flow/scripts/tapcell.tcl
+++ b/flow/scripts/tapcell.tcl
@@ -1,7 +1,7 @@
 source $::env(SCRIPTS_DIR)/load.tcl
 erase_non_stage_variables floorplan
 
-load_design 2_2_floorplan_macro.odb 2_1_floorplan.sdc
+load_design 2_2_floorplan_macro.odb
 source_step_tcl PRE TAPCELL
 
 if { [env_var_exists_and_non_empty TAPCELL_TCL] } {
diff --git a/flow/scripts/util.tcl b/flow/scripts/util.tcl
index 09ab88033a..c8cd77a538 100644
--- a/flow/scripts/util.tcl
+++ b/flow/scripts/util.tcl
@@ -97,31 +97,11 @@ proc extract_stage { input_file } {
   }
 }
 
-proc find_sdc_file { input_file } {
-  # canonicalize input file, sometimes it is called with an input
-  # file relative to $::env(RESULTS_DIR), other times with
-  # an absolute path
-  if { ![file exists $input_file] } {
-    set input_file [file join $::env(RESULTS_DIR) $input_file]
-  }
-  set input_file [file normalize $input_file]
-
-  set stage [extract_stage $input_file]
-  set design_stage [lindex $stage 0]
-  set sdc_file ""
-
-  set exact_sdc [string map {.odb .sdc} $input_file]
-  set sdc_files \
-    [glob -nocomplain -directory $::env(RESULTS_DIR) -types f "\[1-9+\]_\[1-9_A-Za-z\]*\.sdc"]
-  set sdc_files [lsort -decreasing -dictionary $sdc_files]
-  set sdc_files [lmap file $sdc_files { file normalize $file }]
-  foreach name $sdc_files {
-    if { [lindex [lsort -decreasing -dictionary [list $name $exact_sdc]] 0] == $exact_sdc } {
-      set sdc_file $name
-      break
-    }
-  }
-  return [list $design_stage $sdc_file]
+# The stem ends at the first dot of the file name, so 4_cts.odb,
+# 4_cts.odb.def and 4_cts.odb.v all have 4_cts.sdc
+proc sdc_file_of { design_file } {
+  regsub {\.[^/]*$} $design_file .sdc sdc_file
+  return $sdc_file
 }
 
 proc env_var_equals { env_var value } {
@@ -453,6 +433,7 @@ proc orfs_write_db { output_file { endpoint_slack 1 } } {
   if { !$::env(WRITE_ODB_AND_SDC_EACH_STAGE) } {
     return
   }
+  orfs_write_sdc [sdc_file_of $output_file]
   log_cmd write_db $output_file
 }
 
@@ -464,8 +445,8 @@ proc orfs_write_sdc { output_file } {
 }
 
 # For a stage that leaves the design unchanged, copying the input .odb
-# forward is much faster than serializing the in-memory database again
-# with write_db. Gated like orfs_write_db: in a single-process flow
+# and .sdc forward is much faster than serializing the in-memory database
+# again with write_db. Gated like orfs_write_db: in a single-process flow
 # (WRITE_ODB_AND_SDC_EACH_STAGE=0) the input file may not exist and no
 # stage file should be produced.
 #
@@ -477,6 +458,7 @@ proc orfs_copy_db { input_file output_file } {
   if { !$::env(WRITE_ODB_AND_SDC_EACH_STAGE) } {
     return
   }
+  log_cmd exec cp [sdc_file_of $input_file] [sdc_file_of $output_file]
   log_cmd exec cp $input_file $output_file
 }
 
diff --git a/flow/util/write_rc.tcl b/flow/util/write_rc.tcl
index 62922b2b39..190aee2a39 100644
--- a/flow/util/write_rc.tcl
+++ b/flow/util/write_rc.tcl
@@ -1,5 +1,5 @@
 source $::env(SCRIPTS_DIR)/load.tcl
-load_design 6_final.odb 6_final.sdc
+load_design 6_final.odb
 
 source $::env(UTILS_DIR)/write_rc_helper.tcl