• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

which type of tap to buy?

Share this page

J

jwolff

Jedi Hopeful
Offline
I'm getting ready to order a tap to clean out threads in my TR3 while I'm placing an order at mcmaster.com. I need 1/4"- 28 for most holes, correct? Can anyone advise me as to what style of chamfer would be best (taper,plug, or bottoming): https://www.mcmaster.com/#taps/=e9bkge ?
Thanks in advance for any advice,
Jason
 
Ideally you would get a "chaser" or "restorer", something like:

https://www.amazon.com/Mstc-RC7-Rethreadi...8778&sr=8-3

Not sure what threads you are looking at, but on my 4A, 1/4", 5/16" and 3/8" (all fine thread) covers about 95% of the bolts.

PS I realize the set I linked was metric, just using it as an example.
 
That's a good size but you might want to look for a set of "restoring or rethreading taps and dies" for your project. They are made to do what it looks like you want to do and not for cutting new threads.
JVV
 
SInce they're not a King's Ransom to buy, get all three. That'll let you tap new threads as well as clean up. You'll need other sizes too.

My local hardware store (True Value) has a good range of taps and dies. YMMV.
 
Plug style will do fine. 1/4-28 will cover probably 95% of the body bolts. Watch out for smaller holes that are BA (British Association) threads, though. Some are and some aren't on a TR3; and running a 10-32 tap through a 2BA hole will make a mess.

Sears carries a nice set of rethreading taps & dies for about $50; but I've always used ordinary HSS plug taps.

Don't forget you'll want something to turn it with as well. For chasing those zillions of captive nuts in the body, my favorite is a T-handle tap wrench that has a 3/8 square drive in the top so I can use an air ratchet to turn it.
 
Thanks for all of the information. I have a tap and die set but it doesn't have the 1/4-28, just 1/4-20. Glad to see I can use ordinary taps instead of having to order a special re-threading tap set.
 
what kind of tap to buy?

Beer of course
 
TR3driver said:
... Watch out for smaller holes that are BA (British Association) threads, though. Some are and some aren't on a TR3; and running a 10-32 tap through a 2BA hole will make a mess...
Click to expand...

I bought my BA taps from British Fasteners. The 2BA and 4BA are all that I found on the car. The 2BA size is the larger of the two, and as Randall says, it's <span style="font-weight: bold">almost</span> a 10-32, with something like 31.4 tpi. Also the angle of the threads is different. There are 2BA threads on the windshield assembly, and IIRC there are 4BA holding on the toilet seats on the spare tire lid.
 
Hi Art,
Thanks for the link and info on which sizes to get, I wasn't aware of that company... looks like a good resource.

Jason
 
When I set up my shop I bought the Harbor Freight 60 piece nitride coated set for less than $50. The only problem was the brace for holding the taps broke very quickly which I was able to replace with an Irwin tool for only $12. Other than that I have been really happy with the set and best of all it includes all the tap and die sizes I'll ever need in one box with two thread finders and case with clear markings for each item.
 
The Machinery Handbook from Industrial Press has a wealth of knowledge regarding things such as the different classes of taps and dies speeds to use when drilling different materials etc. A bit pricey but worth it.

Jim
 
Back
Top