

What is this Major Spline Diameter?
Spline data says:
External Spline to fit internal stub tooth spline
Flat rootSide fit
12 Teeth 32/64 Pitch
.375 Pitch Diameter30' Pressure
angle per ANSI B92.21996
Guys over at the gear house are telling me to turn them to .405/.406
When I calculate per the handbook I am coming out with a number about .004 smaller.I'm sure these guys are right as they do this kind of stuff all day long but since I have never used this place before I want to be certain.
Anyone know what the major diameter should be?

Download this as a trial version.
Involute Gear and Spline Software
JR

Originally Posted by Metal Slave
Spline data says:
External Spline to fit internal stub tooth spline
Flat rootSide fit
12 Teeth 32/64 Pitch
.375 Pitch Diameter30' Pressure
angle per ANSI B92.21996
Guys over at the gear house are telling me to turn them to .405/.406
When I calculate per the handbook I am coming out with a number about .004 smaller.I'm sure these guys are right as they do this kind of stuff all day long but since I have never used this place before I want to be certain.
Anyone know what the major diameter should be?
First, Isn't SAE B92.2M for metric? I think that the spec you want is SAE B92.1, which is in inch measure.
I think that the pressure angle is 30° , not 30'. (to get the degree sign, hold down the alt key and type 0176 on the numeric keypad).
For flat root, side fit, 30° PA, 12 teeth, 0.375 pitch diameter,
D=N/P, or so diametral pitch is 32 consistent with your pitch and stub pitch diameters of 32/64, consistent with the spec.
The major diameter for an external spline is
Do = (N+1)/P = 0.4063" consistent with your calculation.
There is "Form Diameter" and clearance (Cf=0.001D, or 0.0041 in this case), so check the spec and get the experts here to confirm, but I think that you got your OD right and it should be 0.406. To check, the internal spline major diameter (root) I calculate for this setup is:
Dri = (N+1.35)/P = 0.4172. Your external spline OD of 0.4063", plus the tolerance of 0.0041, gives you 0.4104", which is less than 0.4172 by 0.0068 inches. That is, you have 3 thousandths clearance on this unit. I can't see why you'd use less than 0.406 on the OD.
But check with experts. I'd been researching involute splines for a drill press quill. My source was page 2071 et seq. of Modern Machine Shop's Handbook for the Metalworking Trades, and this book cites the 92.1 specification.
J
Last edited by bosleyjr; 08302010 at 07:12 PM.
Reason: spelling, punctuation


per ANSI B92.1
.392.406__________________________

Thanks guys
The spec is B92.1,I must have typed it in wrong

Still a little confused though as the formula I have for a Flat root Side Fit shows
N/P + .8/P .004
For Fillet Root Side Fit it shows N+1/P
Wondering if my handbook is outdated?
Posting Permissions
 You may not post new threads
 You may not post replies
 You may not post attachments
 You may not edit your posts

Forum Rules

Bookmarks