Limits and Fits for conical taper surface 1

[SeasonLee]

We know ANSI B4.2-1978(R2004) is the standard for selecting size tolerance, but that is for the features like pins and holes or bearings and shafts etc., if the feature (for example pins and holes) with a conical taper surface, what is the Limits and Fits standard for these kind of features? Is the standard ANSI B4.2-1978(R2004) still applicable?

Thanks for the help, please let me know if this forum is not the right place to post this question.

Season

 

[desertfox]

Hi Seasonlee

I believe the same standard covers for tapered components as well as the normal cylinderical ones.
What would normal happen with a tapered component would be to select a reference point on the taper and dimension it accordingly and apply the same logic to the mating part.

 

[tbuelna]

SeasonLee-

ANSI B4.2 and B4.1 provide a standardized method of defining ID/OD fits for cylindrical components. There are other standards for specific taper fits such as ANSI B5.10.

The primary reason for using a tapered connection is to ensure intimate contact between the mating joint surfaces for purposes of accurate alignment or torque transfer. And this intimate contact condition is achieved by applying a relative axial displacement between the mating components. Unlike joints between cylindrical components, there would seem to be no logical reason for having radial clearance between components in a tapered joint.

Hope that helps.
Terry

 

[MikeHalloran]

It's a good question.

Unfortunately, the answer, regardless of what standard might apply to shafts and straight bores, is that you need to specify a very tight tolerance on the cone angle for both male and female parts, especially if they come from different sources.

See reference material on, e.g., Morse tapers and such.




Mike Halloran
Pembroke Pines, FL, USA

 

[SeasonLee]

Thanks for all comments

Season

 

[ALREMAN]

Seems like the purpose of a tolerance on this type of joint would be to control the depth of engagement, rather than the freedom to assemble, turn, etc. like in ANSI B4.1/2. What is the design intent of this joint?

 

[SeasonLee]

Alreman

Sorry for we can't provide further information since we are just a manufacturer.

Season