Question: tap and die set sizes

[Hanno Spoelstra]

I can buy a tap and die set at a discount with the following sizes:

BSW 1/8 - 40, 5/32 - 32, 3/16 - 24, 7/32 - 24, 9/32 - 20, 3/8 - 16,
BSW 7/16 - 14, 5/16 - 18, 1/2 - 12 / 9/16 - 12, 5/8 - 11, 3/4 - 10
BSF 3/16 - 32, 7/32 - 28, 1/4 - 20, 1/4 - 26, 9/32 - 26, 5/16 - 22,
BSF 3/8 - 2-, 7/16 - 18, 1/2 - 16, 9/16 - 16, 5/8 - 14, 3/4 - 12.
BSPT 1/8 - 28, 1/4 - 19
Metrisch M6 x 1,0 / M8 x 1,25 / M10 x 1,5 / M10 x 1 / M11 x 1,5
Metrisch M12 x 1,25 / M12 x 1,75 / M14 x 1,25 / M18 x 1,5

Question: are these of any use for the Ford CMP truck?

Thanks,
Hanno

[gjamo]

Hanno,
The sizes are OK for your CMP. The important question is the material they are produced from. High Speed Steel (HSS) was the traditional material of high quality tooling. Recently cheap and nasty taps and dies are being manufactured in carbon steel and are at best useless.
Graeme

[Hanno Spoelstra]

Graeme,

Thanks for your reply. Somehow I have problems remembering what thread types are applicable to CMPs, being a British design built in North America. BSW, BSF, BSPT, UNC, UNF, blah, blah, etcetera.

Hanno

[Local Chap]

Originally Posted by gjamo

Hanno,
The sizes are OK for your CMP.
Graeme

I don't think they are!!!

Most of the threads on a CMP will be UNF or UNC (with some NPT on fuel and brake lines). There are certainly NO Metric threads, and the minimal amount of BSF threads found are specific to particular items carried across from Brit WD practice. In fact, the only BSF thread I can think of is not in the kit, 7/8-11tpi for the divided wheel nuts/studs

[Lynn Eades]

Your CMP will be as the "Local Chap" (who needs a name)said. It was built with all UNF, and UNC fasteners. If it has any BSF, then take them off and give them to a Carrier owner or a Brit motor bike owner. The Tap and Die set is no use for the truck.

[Mike Kelly]

HANNO


British BSW ( british standard whitworth) threads will interchange with UNC American threads ..... BSW has a 55 degree thread angle and UNC is 60 degrees.. but for practical purposes .. they fit OK .. EXCEPT for the 1/2" size ..this size has different TPI threads per inch .

The BSF .. (british standard fine) threads are found on British MAKES .... my Morris has them everywhere ... along with metric threads on the motor .

Mike

[Phil Waterman]

Hi All

Would add the comment I own one very good set of taps and dies which I use only for cutting new threads or chasing really important existing threads.

For all work cleaning threads of dirt and in particular rust I use the cheap taps and dies which I consider consumables once they start to dull.

For cleaning threads I have also found that the twisted wire brushes in various sizes are very useful, particularly with blind threaded holes. A low speed reversible variable speed drill works well running back and forth through.

Cheers Phil

[Alex van de Wetering]

Hanno,

Just like you I also have to look for a set of taps and dies for the CMP; I know some good quality ones do pop up on marktplaats.nl every once in a while; although usually not as a set, but as separate items, so you might have to keep and eye out to gather a whole set.
I have also seen good quality USED ones at the yearly KTR fair in Breda and at Baco in IJmuiden (only the smaller sizes though).

Alex

[Hanno Spoelstra]

Thanks all for the replies!

It proves how confusing it is to work on a vehicle which was built in North America from British specifications.

See http://en.wikipedia.org/wiki/Screw_thread for a nice overview of screw thread standards etc.

Regards,
Hanno