Valid

GB/T 28251-2012The technical specifications for timing belt wheel hobs and timing belt mold hobs (English PDF)

带轮滚刀和带模滚刀技术条件

Preview PDF

This is a limited preview

Buy now to download the full PDF (15 pages)

Need quotation for your management?

Get a formal quotation for GB/T 28251-2012 in 30 minutes.

Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

March 9, 2012

Implementation date

July 1, 2012

Scope

GB/T 28251-2012 is the English-translated version of 带轮滚刀和带模滚刀技术条件.

GB/T 28251-2012 is the Chinese standard "The technical specifications for timing belt wheel hobs and timing belt mold hobs". Its scope clause reads: This standard specifies the basic requirements for the technical requirements, marking and packaging of pulley hobs and die hobs.

This standard is applicable to pulley hobs and die hobs machined according to GB/T 28249 and GB/T 28250. Its clauses include normative reference documents; technical requirements.

Found what you need?

Document preview — GB/T 28251-2012

National Standard of the People's Republic of China

ICS: 25.100
Classification: J 41

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

Foreword
1 Scope
2 Normative references
3 Terms and definitions

1 Scope

This standard specifies the basic requirements for the technical requirements, marking and packaging of pulley hobs and die hobs.

This standard is applicable to pulley hobs and die hobs machined according to GB/T 28249 and GB/T 28250.

2 normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article

Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB/T 28249 pulley hob type and size

GB/T 28250 with die hob type and size

3 technical requirements

3.1

The surface of the hob shall not be cracked, burnt and other defects that affect the performance.

3.2

hob surface roughness of the upper limit according to Table 1.

Table 1 units are microns

Check surface roughness parameters Surface roughness values

Bore surface

Axis end face

Outer cylindrical surface

Knife front

Behind the teeth

The top of the tooth

0.63

1.25

0.63 3.3 hob outside diameter limit deviation by h15, the total length of the limit deviation by js15.

3.4

The main tolerances for hob manufacturing are as specified in Table 2.

Table 2 units in millimeters

No. Inspection item tolerance code

Pitch

Lt;/RTI & gt;

tolerance

1 aperture limit deviation deltaD H6

2 Radial runout of the axis of the inner bore axis deltadir 0.008 0.010 0.012

3 axis of the end of the hole on the axis of the round runaway deltadix 0.006 0.008 0.010 […]

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 15 pages — is available in the English PDF.

Similar standards

GB/T 28249-2012|GB/T 30470-2026|GB/T 47571-2026|GB/T 47927-2026|GB/T 2476-2025|GB/T 28253-2025

How to Download GB/T 28251-2012

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.