In the transmission book Fred Houston recommends reusing old magnet screws as much as possible because the modern ones are made of low quality brass that's brittle and likely to break. But that was published twenty-five years ago. How about the screws currently available. Are they OK?
I reused mine in my 16 with no issues. They came out pretty easy as along as your screw driver blade width matches the screw slot width.
Ironically you ask that question today. Almost to the day, one year ago, Roger said why to not re-use them. However, other posters do.
Decisions - Decisions....good luck !
I used "new" screws from a T parts supplier several years back and they are doing fine. Brass tends to work harden and crack over time. I don't think I'd re-use and old one if I didn't have to. I have not really looked at those screws much, to see what they were originally. I have used silicon bronze screws in other areas. They are a "strong" brass screws.
I have wondered about the same thing over the years when putting together a flywheel. I have a bunch of them I saved because they were still good.
But I always used new ones because they were available.
I have a feeling that in the 'old days' people would reuse them if they were still good.
The same goes for the ring gears. There was an engine builder at Chickasha a few years ago who had some really nice ( I thought ) ring gears he removed from engines and installed new ones instead. I bought one from him for an extra for $5.00. Now I wish I would have bought the rest.
To each his own.
I agree with Verne. The heads of the screws break off at the bottom of the slot. I lost one but heard the clamp make a round when I started the car. Just very lucky. From another thread:
When I pulled the hogshead, I found two more screws with half of the head missing but the clamp was still in place.
I was able to change the screws in the car without pulling the engine. The July 1913 engine in my car has a DB coil ring with a hole for that purpose.
The screws are #14-24 ASME but it is a little hard to see in the drawing. If you use your original non-starter flywheel, you need #14-24 ASME screws. New screws all around for me when I rebuilt the engine.
There are some 1/4-24 starter ring gears so check what you have. The screws are only ten bucks or so.
Ken in Texas
I've used new brass in the past but wondered why one couldn't use stainless in 1/4-28. That's what I used on my HCCT and it doesn't cause an issue as far as the magneto is concerned. Of course the ring gear would need to be turned and redrilled / tapped to do that but no big deal.
Anyone do this already?
If work hardening is the concern, why couldn't one just re-anneal the brass screws to soften them again?
Those plates held in place with the brass screws might be a better part to reuse.
The new ones are much softer and easy to bend to a loose position.
I have done both old and new with no problems. The brass is not going to work harden in place. When reusing a ring gear its good practice to rotate the ring gear 90 degrees so the Bendix is working a new spot. I have done that and re- used the screws with out a problem. A good visual check of the screws is required .