British Standards Institution

Source:: ISO
Committee:: ACE/12 - Aerospace fasteners and fastening systems
Categories:: Information management | Standardization. General rules

Scope

This standard describes the dimensions of hexagonal head bolts, with large tolerance normal shank and UNJF threads, in metallic material (alloy steel, CRES and titanium alloy, etc.), coated or uncoated. It is applicable to be used as a test bolt for torque-tension tests of self-locking nuts and threaded collars to determine locking torque, breakaway torque and preload.

Purpose

High demand for the aerospace fastener industry, OEMs and laboratories. Various tests have been performed as a basis for the test bolt definition, and the test bolt standard for metric (MJ) threads has been published (ISO 6397) in 2024. This new standard will be complementary to ISO 6397, focusing on imperial (UNJF) threads.

Comment on proposal

Required form fields are indicated by an asterisk (*) character.

How important do you think standardization is in this area? *

Do you agree that a standard on this subject is feasible?: *

Please give reasons for your selections above: *

Would you or your organization use the standard? *

Would you or your organization be prepared to participate in the development of the standard or to comment on the draft when it is available? *

Are you aware of any regulation, existing standards and other good practice information in this area in the UK (e.g. Industry codes of practice; company specifications, international or European Standards)? *

Would the development of a standard(s) in this area have a particular impact/relevance to SME, consumer, environmental or societal interests? *

Are you aware of any other organizations to which this proposal may be relevant? If so please provide details below. *

Additional comments on the scope or proposal:

Although BSI will not usually enter into correspondence regarding individual comments or suggestions we may wish to contact you to seek further clarification. Please indicate whether this will be acceptable: *

Discard

Please email further comments to: debbie.stead@bsigroup.com

Standard timeline

1. Proposal

Proposal start date:

10/06/2025

Proposal end date:

02/08/2025

2. Draft

3. Public Comments

4. Comment Resolution

5. Approval

6. Publication

Learn more about the standards development process

Standards Development

ISO/NP 25963 Aerospace — Test bolts, hexagonal head, UNJF threads, metallic material, coated or uncoated

Scope

Purpose

Comment on proposal

Discard changes?

Submit comment

Submit comment

Follow standard

Unfollow standard

Error