diff --git a/form3/obj3/thread/acme.go b/form3/obj3/thread/acme.go
index 0c9e044..3c5e6ed 100644
--- a/form3/obj3/thread/acme.go
+++ b/form3/obj3/thread/acme.go
@@ -17,8 +17,8 @@ type Acme struct {
 
 var _ Threader = Acme{} // Compile time check of interface implementation.
 
-func (acme Acme) Parameters() Parameters {
-	return basic{D: acme.D, P: acme.P}.Parameters()
+func (acme Acme) ThreadParams() Parameters {
+	return basic{D: acme.D, P: acme.P}.ThreadParams()
 }
 
 // AcmeThread returns the 2d profile for an acme thread.
diff --git a/form3/obj3/thread/ansibuttress.go b/form3/obj3/thread/ansibuttress.go
index 5cecc24..f889a36 100644
--- a/form3/obj3/thread/ansibuttress.go
+++ b/form3/obj3/thread/ansibuttress.go
@@ -16,8 +16,8 @@ type ANSIButtress struct {
 
 var _ Threader = ANSIButtress{} // Compile time check of interface implementation.
 
-func (butt ANSIButtress) Parameters() Parameters {
-	return basic{D: butt.D, P: butt.P}.Parameters()
+func (butt ANSIButtress) ThreadParams() Parameters {
+	return basic{D: butt.D, P: butt.P}.ThreadParams()
 }
 
 // ANSIButtressThread returns the 2d profile for an ANSI 45/7 buttress thread.
diff --git a/form3/obj3/thread/basic.go b/form3/obj3/thread/basic.go
index 2c06ebc..cc65ad0 100644
--- a/form3/obj3/thread/basic.go
+++ b/form3/obj3/thread/basic.go
@@ -10,7 +10,7 @@ type basic struct {
 	P float64
 }
 
-func (b basic) Parameters() Parameters {
+func (b basic) ThreadParams() Parameters {
 	radius := b.D / 2
 	return Parameters{
 		Name:   "basic",
diff --git a/form3/obj3/thread/bolt.go b/form3/obj3/thread/bolt.go
index e6a8459..38058a0 100644
--- a/form3/obj3/thread/bolt.go
+++ b/form3/obj3/thread/bolt.go
@@ -31,7 +31,7 @@ func Bolt(k BoltParms) (s sdf.SDF3, err error) {
 	case k.Tolerance < 0:
 		err = errors.New("tolerance < 0")
 	}
-	param := k.Thread.Parameters()
+	param := k.Thread.ThreadParams()
 	// head
 	var head sdf.SDF3
 
diff --git a/form3/obj3/thread/iso.go b/form3/obj3/thread/iso.go
index 44fc9ed..e7c52cd 100644
--- a/form3/obj3/thread/iso.go
+++ b/form3/obj3/thread/iso.go
@@ -21,9 +21,9 @@ type ISO struct {
 
 var _ Threader = ISO{} // Compile time check of interface implementation.
 
-func (iso ISO) Parameters() Parameters {
+func (iso ISO) ThreadParams() Parameters {
 	b := basic{D: iso.D, P: iso.P}
-	return b.Parameters()
+	return b.ThreadParams()
 }
 
 func (iso ISO) Thread() (sdf.SDF2, error) {
diff --git a/form3/obj3/thread/knurl.go b/form3/obj3/thread/knurl.go
index f9603f9..94365d6 100644
--- a/form3/obj3/thread/knurl.go
+++ b/form3/obj3/thread/knurl.go
@@ -36,8 +36,8 @@ func (k KnurlParams) Thread() (sdf.SDF2, error) {
 }
 
 // Parameters implements the Threader interface.
-func (k KnurlParams) Parameters() Parameters {
-	p := ISO{D: k.Radius * 2, P: k.Pitch, Ext: true}.Parameters()
+func (k KnurlParams) ThreadParams() Parameters {
+	p := ISO{D: k.Radius * 2, P: k.Pitch, Ext: true}.ThreadParams()
 	p.Starts = k.starts
 	return p
 }
diff --git a/form3/obj3/thread/npt.go b/form3/obj3/thread/npt.go
index b01f270..a9345cf 100644
--- a/form3/obj3/thread/npt.go
+++ b/form3/obj3/thread/npt.go
@@ -19,8 +19,8 @@ type NPT struct {
 
 var _ Threader = NPT{} // Compile time check of interface implementation.
 
-func (npt NPT) Parameters() Parameters {
-	p := ISO{D: npt.D, P: 1.0 / npt.TPI}.Parameters()
+func (npt NPT) ThreadParams() Parameters {
+	p := ISO{D: npt.D, P: 1.0 / npt.TPI}.ThreadParams()
 	p.Name = "NPT"
 	p.Taper = math.Atan(1.0 / 32.0) // standard NPT taper.
 	if npt.F2F > 0 {
diff --git a/form3/obj3/thread/nut.go b/form3/obj3/thread/nut.go
index 94da430..a364f9f 100644
--- a/form3/obj3/thread/nut.go
+++ b/form3/obj3/thread/nut.go
@@ -49,7 +49,7 @@ func Nut(k NutParms) (s sdf.SDF3, err error) {
 		return nil, err
 	}
 
-	params := k.Thread.Parameters()
+	params := k.Thread.ThreadParams()
 	// nut body
 	var nut sdf.SDF3
 	nr := params.HexRadius()
diff --git a/form3/obj3/thread/plasticbuttress.go b/form3/obj3/thread/plasticbuttress.go
index 70cd084..b324989 100644
--- a/form3/obj3/thread/plasticbuttress.go
+++ b/form3/obj3/thread/plasticbuttress.go
@@ -16,8 +16,8 @@ type PlasticButtress struct {
 
 var _ Threader = PlasticButtress{} // Compile time check of interface implementation.
 
-func (butt PlasticButtress) Parameters() Parameters {
-	return basic{D: butt.D, P: butt.P}.Parameters()
+func (butt PlasticButtress) ThreadParams() Parameters {
+	return basic{D: butt.D, P: butt.P}.ThreadParams()
 }
 
 // Thread returns the 2d profile for a screw top style plastic buttress thread.
diff --git a/form3/obj3/thread/thread.go b/form3/obj3/thread/thread.go
index e72f1cf..61a7ae9 100644
--- a/form3/obj3/thread/thread.go
+++ b/form3/obj3/thread/thread.go
@@ -24,7 +24,7 @@ import (
 
 type Threader interface {
 	Thread() (sdf.SDF2, error)
-	Parameters() Parameters
+	ThreadParams() Parameters
 }
 
 type ScrewParameters struct {
@@ -59,7 +59,7 @@ func Screw(length float64, thread Threader) (sdf.SDF3, error) {
 	if err != nil {
 		return nil, err
 	}
-	params := thread.Parameters()
+	params := thread.ThreadParams()
 	s := screw{}
 	s.thread = tsdf
 	s.pitch = params.Pitch
diff --git a/form3/obj3/thread/uts.go b/form3/obj3/thread/uts.go
index fb671bc..d6beb0e 100644
--- a/form3/obj3/thread/uts.go
+++ b/form3/obj3/thread/uts.go
@@ -14,8 +14,8 @@ type UTS struct {
 
 var _ Threader = UTS{} // Interface implementation.
 
-func (uts UTS) Parameters() Parameters {
-	p := basic{D: uts.D, P: 1.0 / uts.TPI}.Parameters()
+func (uts UTS) ThreadParams() Parameters {
+	p := basic{D: uts.D, P: 1.0 / uts.TPI}.ThreadParams()
 	// TODO(soypat) add imperial hex flat-to-flat. See NPT for what that could look like.
 	return p
 }