This is about The BettyAnne, my 1925 Stanley SV 252G. Coming off the top of the rear end is a long aluminum casting that carries a heavy shaft geared to the spur gear in the rear end. It follows the axel for a foot or so, then through a worm gear turns 90 degrees and heads up to the pump pit.

When I disassembled this part, the steel machine screw heads were very badly rusted, indeed in several cases I resorted to vice grips to get a grip on them. They came out without damage, and I took a sample to Turner Hardware (the best hardare store in Texas) and bought 1/4-20 machine screws to replace the rusted screws, matching old screw to new screw. Simple enough, but the new screws did not fit in to old holes.

So I put the micrometer on the old screws and on the new screws and discovered that there was a .006 - .008 difference, the old screws being smaller. A standard 1/4-20 tap cleans out the soft aluminum holes and the new screws fit just fine. Why the difference?

My long time clock collector friend, Don Brown, then told me about "Burroughs Bastard Standards." He started his career in the 1950s at Burroughs before jumping to Chrysler. According to Don (Brown, not Hoke) many large companies had screw thread standards that were note exactly National Fine or National Course.

Indeed, according to Don (Brown, not Hoke) if you needed a screw to fix your Burroughs adding machine, you bought it from Burroughs because a standard screw would not fit. Don helped to design the first Burroughs machine that used N/F & N/C threads.

So what is going on in the car industry in the 1920s? Every other nut and bolt on The BettyAnne is standard. I've replaced dozens of rusted nuts with nuts straight from Turner Hardware. Why the difference on this strange pump driving part?

Has anyone had issues with screw threads in restoring Stanleys? Did they use N/F & N/C or did they have their own "Stanley Bastard Standards?"

Thanks!

Don Hoke

Wanted: Parts for 1924 Stanley Model 750 and 1925 Stanley Model SV 252. We buy steam car parts and literature. Visit the virtual steam car museum at www.virtualsteamcarmuseum.org.

For all your steam car needs, visit www.vintagesteamproducts.com.

Don,

I worked for a company that had the very idea you desribe. They sold machines with a key part held on with a "special high strength screw - must be bought from us."

Actually the screws were 14-20 standard, now obsolete. They are still used in a few places. You can still buy them but not much reason for going to the trouble since 1/4-20 fits if (as you point out) a tap is first used to clean out the holes.

All the screw sizes are listed in the old handbooks, search Google Books, "14-20 screw threads, full view".

A bigger problem is the different appearance of modern cold headed bolts so unlike the plain flat topped hex of oldtime machined bolts.

John Buscher

Thanks, John!

You're right about the appearance. As a recovering Museum Curator and Director, I am doing what might be called a "sympathetic restoration" on The BettyAnne.

I am trying to use all the original parts and keep the car as original as possible. This results in dozens of decisions - how much to restore and how much to leave as found.

With the nuts and bolts, I am reusing as much of the original hardware as possible and when I replace completely corroded nuts and bolts, I do so with the Grade 8 hardware, not because it is needed, but so that anyone looking at the car will know it is a replacement.

The car will come with a manual describing the restoration as well as all the parts replaced during the restoration.

Best wishes!

Don Hoke

Wanted: Parts for 1924 Stanley Model 750 and 1925 Stanley Model SV 252. We buy steam car parts and literature. Visit the virtual steam car museum at www.virtualsteamcarmuseum.org.

For all your steam car needs, visit www.vintagesteamproducts.com.