What sort of thread is 1/4- 32UNS -2A?

This topic has 5 replies, 3 voices, and was last updated 20 May 2015 at 18:03 by Steve Withnell.

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17 May 2015 at 22:14 #190376
Steve Withnell
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@stevewithnell34426
Is this normally referred to as 1/4 – 32 UNEF?

2A appears to be the thread tolerance.

Steve
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17 May 2015 at 22:14 #7627
Steve Withnell
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@stevewithnell34426
17 May 2015 at 22:36 #190378
Tony Brazier
Participant
@tonybrazier31255
Hi that the same as glow plug thread for glow engines.

Tony
17 May 2015 at 22:45 #190380
Enough!
Participant
@enough
UN standards are:

UNC – coarse
UNF – fine
UNEF – extra fine
UNS – special (pitches not covered by the other categories)
UNR – must have root radius

1/4 – 32 is specified in the UNEF category. I don't know why it would be described as UNS.

Thread classes are 1A/2A/3A and 1B/2B/3B the number being the fit (1=loose to 3=close). A is used for external threads; B for internal
18 May 2015 at 20:27 #190511
Steve Withnell
Participant
@stevewithnell34426
Posted by Tony Brazier on 17/05/2015 22:36:47:

Hi that the same as glow plug thread for glow engines.

Tony

Thanks for that – I must have one in the box then!

Steve
20 May 2015 at 18:03 #190716
Steve Withnell
Participant
@stevewithnell34426
Hmm the nuts that I have which are specified as 1/4- 32UNS -2A, don't fit the enya glow plugs I have. The pitch is off just enough so the nuts don't run on to the plug thread. Don't worry, I'm not intending to fit nuts to my plugs, it was just an easy way to test Tony's point above.

Steve
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What sort of thread is 1/4- 32UNS -2A?

What sort of thread is 1/4- 32UNS -2A?

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