Lock Plugs 1

[Eddieeeeeee]

I am looking for a specification, standard or industry guidline that documents the required diameter of a lock plug based on thread pitch.

Can someone post a link to a site where I can view or down-load a chart or document?

Thanks in advance

 

[MikeHalloran]

I wasn't aware they were required to be any particular size.
... or round, for that matter.

Perhaps we are talking about different things?



Mike Halloran
Pembroke Pines, FL, USA

 

[Eddieeeeeee]

Hi Mike,

There are definitely requirements. I have a very old and fragile document but very little of it is legible.
I can only make out two of the entries:
THREAD PITCH PLUG DIA
80 .031
32 .062

That's all I've got.

 

[MintJulep]

Relevant standards are:

MIL-DTL-18240: Performance specification for prevailing
torque type fasteners performing to +250°F — both external
and internal threads. Defines patch, strip, and pellet type configurations
and offers 5 cycle reusability and torque performance
requirements.

IFI 124: Industrial Fastener Institute commercial performance
standard and test procedure for prevailing torque type fasteners
using non-metallic locking elements. Offers 5 cycle reusability
and torque performance requirements.

IFI 524: Same as IFI 124, but for metric size thread forms.
NAS 1283: Design standard for male threaded self-locking
fasteners. Incorporates MIL-DTL-18240 performance standards
and test requirements by reference.
MS 15981: Design standard for design and usage limitations
of externally threaded self-locking fasteners. Incorporates MILDTL-
18240 performance standards and test requirements by
reference.

MIL-F-8961: Design and performance standard for high temperature
(450°F + 1200°F) externally threaded self-locking
fasteners. Offers 15 cycle reusability and torque performance
requirements.

MIL-I-45932: Design and performance standard for thin wall,
self-locking screw thread inserts. Includes design, performance
and torque requirements for integral locking device type, both
metallic and non-metallic.

MIL-S-82496A: Procurement specification for integral O-ring,
self-sealing machine screws. Offers design, performance and
test requirements for self-sealing fasteners including reusability
and minimum pressure sealing capability.
IFI 125: Industrial Fastener Institute commercial performance
and test procedure for chemically coated (pre-applied and assembly-
applied adhesive) lock screws. Offers prevailing and
breakaway torque performance criteria
IFI 525: Same as IFI 125, but for metric size thread forms.

 

[Eddieeeeeee]

Hey, thanks Mint,

That's a lot of information!

I was finally able to put together a chart that meets my needs, it is quite simply:

THREAD PITCH/PLUG DIA
80/.031
64/.031
56/.046
48/.046
40/.062
36/.062
32/.062
28/.093
24/.093
20/.125
18/.125

Once again, thank you for all the sources.