Packard Forum Index » General

kts68, a great currently in-print reference source witn more than you ever wanted to know about threads and threading, NC, NF, UNC, SAE, Whitworth, Acme, metric, NPT, classes of fit, and the like is pictured below from a previous post. Don't know of it's availability in the UK but I'd consider it nearly indispensable for any serious old car person. I also has a very useful section on chemical formulas for metal finishing. Highly recommended, and for far more than just the info on threads, metal treating, etc.

Later today I'll risk copyright issues and just excerpt a very small section on US threads so you can sample the type of information. I'll add it here rather than start a new post.

Attach file:

---

  (18.18 KB)


  (98.56 KB)

Great advice, thanks to all

Thanks Owen for the glossary picture of the head styles - very useful.

I do have a bucket full of nuts bolts and screws but they are all metric and I dont want to alter original threads unless necessary.

I'll look to build up a stock of UNF nuts & bolts as suggested. I can get them locally as per this UK supplier

Thanks again

Attach file:

---

  (44.82 KB)

Owen it is permissible to quote a book when reviewing it so your excerpt should qualify.

kts68 I live in Canada and used to work on English cars and motorcycles not to mention American, European and Japanese. So maybe I can offer some insights on this.

American and English standards were set up differently. Spcifically, English bolts and nuts are sized by the head and American by the shank. So for example, an American 1/2" bolt will be quite large, equal to a half inch drill while an English 1/2 will be much smaller. This applies specifically to wrench sizes.

Another thing about wrench sizes. As near as I can make out, the first guy to make a bolt and a wrench in the UK made the wrench first then made the bolt head a hair smaller so the wrench would fit easily. While the American made the bolt first then made the wrench a hair bigger. This is why the wrenches look like they will fit but never do.

And of course, thread specs are completely different.

In the old days, meaning before 1968 Ford used a lot of American sized fasteners or so I am told. Then there was the Unified thread standard, really American standard, that was used from 1968 or 69 as long as the motorcycle industry lasted. So, I hope you can get American or UNF wrenches and fasteners locally.

Since were dealing with 30's model car here it is important to note that there are 2 different series of standard size US bolts and nuts. One is a series 36 the other a series 64. I'm sure about the 36 and 64 but it will be in and about the 36 and 64 years. Such as 1936 and 1964.

The earlier series had series 36 had a 1/64 less diameter on shoulder nolts and the heads were 1/64 shorter. Possibly nuts were 1/64 inch shorter too.

Probably not a big issue but something to keep in mind if there is a fit problem.

Beware of a few bastardizations of Imperial bolt sizes:
There is a #12 Screw size in both coarse and fine thread. The #12 is almost the same size as a very common 1/4" size.
The #12 is often difficult to find even at better hardware stores.

There is also a 1/2-12 and a 1/2-13 thread. The 13 TPI is not often used but it does show up from time to time.

Just so you know, I looked for the Machinist and Metal Worker Pocket Reference on Amazon, and it is now out-of-print. However, there is a Kindle (ebook) version available.

Tom, hope you go for it and find it as useful as I have. There were copies on the shelf at the local Barnes & Noble about a week ago, and thanks for letting me know it's out of print.