Ring & Plug Thread Gages  
 
Call 616 954 6581 for Thread Gages
About Ring & Plug Thread GagesUsed - Surplus Ring & Plug Thread GagesRing & Plug Thread Gage Technical InformationRing & Plug Thread Gage CatalogsContact Ring & Plug Thread GagesBookmark

 

 
 
 
 
 

Centralizing ACME Screw Threads

Centralizing ACME Screw Threads

Centralizing ACME screw threads are defined by ANSI/ASME B1.5.

The thread form for Centralizing Acme threads is the same as General Purpose Acme Threads with the exception that a Centralizing Acme Threads have a limited clearance at the major diameter of both the internal and external threads, and are used extensively for feed screws. The restricted clearance enables a bearing at the major diameter of the thread to preserve alignment of the thread axis preventing wedging on the flanks and part sagging.

Five classes are used with the Centralizing Acme threads: 2C, 3C, 4C, 5C, and 6C. For any combination of the five classes of threads Covered within the standard (ANSI B1.5) some end play or backlash will result. Although 5C and 6C are intended to allow for restricted backlash they are not recommended for new designs.

A series of diameters and pitches is recommended in the Standard as preferred. These Diameters and Pitches have been chosen to present needs with the fewest number of items to reduce inventory of both tools and gages. The tolerances specified in this standard are applicable to lengths of engagement not exceeding twice the nominal major diameter as well as to insure interchangeability and maintain a high grade of product. The tolerances on the diameters of internal threads are plus, being applied from the minimum sizes to above the minimum sizes. The tolerances on the diameters of external threads are minus, being applied from the maximum sizes to below the maximum sizes. The pitch diameter tolerance for internal or external threads for any given class is the same.

Below are examples of the proper nomenclature for single and multi-start Centralizing Acme Threads:

Single Start: 1.250"-5 ACME-2C or 1-1/4"-5 ACME-2C
1.250-inch major (nominal) diameter, 5 threads per inch, single thread, Class 2C fit, right hand

Multi-Start: 2.750"-0.4P-0.8L-ACME-3C or 2-3/4"-0.4P-0.8L-ACME-3C
2.750-inch major diameter, pitch 0.4 inch, lead 0.8 inch, double thread, Class 3C, right hand.

Single Start: 1.250"-5 ACME-2C LH or 1-1/4"-5 ACME-2C LH
1.250-inch major (nominal) diameter, 5 threads per inch, single thread, Class 2C fit, Left hand

Multi-Start: 2.750"-0.4P-0.8L-ACME-3C LH or 2-3/4"-0.4P-0.8L-ACME-3C LH
2.750-inch major diameter, pitch 0.4 inch, lead 0.8 inch, double thread, Class 3C, Left hand.
*
For more information click the links below.
Centralizing Thread Profile
General Purpose ACME Screw Thread Profile
General Purpose Screw Thread Data
Centralizing ACME
3-Gage System VS 4-Gage System
Stub ACME

Disclaimer:
This data is provided for general information only. The intention is to provide accurate information; regardless; errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root document: ANSI/ASME B1.5; which is a copyrighted document. To purchase a copy visit an Authorized Reseller.

Comments:
Original Posting: 7/14/2009
Last Revision: 4/17/2013
Error corrections in, or comments about, the above data can be sent to: gageguy@gagecrib.com

About UsUsed SurplusTech InfoCatalogsContact UsBookmark
 

 

Top

Gage Crib Worldwide, Inc.
6701 Old 28th St SE, Suite B
Grand Rapids, MI 49546-6937
Phone: 001-616-954-6581 • Fax: 001-616-954-6583
CONTACT  FORMS & INFO

Copyright © 2002-2017 Ring & Plug Thread Gages. All rights reserved.