Slitting saws

[Coomba]

I would like to make some screws for an old engine I have. I will more than likely make the arbor. I don't have the screws, as a model to go by. I need suggestions as to what thickness of saw to buy. Should I get a staggered tooth or straight tooth? What would be the average depth of cut? I understand that the thickness, and depth of cut will vary by many factors. General information on the slot size. My average machine screw, would be from 1/4 20, and smaller, but two as large as 3/8.

 

[benmychree]

Look at screwdrivers that the width is the diameter of the screw head that you want to make, measure the thickness of the tip of that screwdriver, and you will get a general idea of the slot you want to cut; the slot should fit the driver snugly, or vice versa; screw slotting cutters are fine toothed and with no fluting on the sides. Look for "screw slotting" cutters, they have straight teeth and a small amount if hollow grind to reduce the tendency to drag on the sides.

 

[4ssss]

Straight tooth slotting saws and plunge the blade into the head. If you look at a screw head you'll see that the bottom of the slot is concave. The bigger the saw diameter the less concave you'll see. On B&S screw machines they used a 2" dia. saw.

 

[francist]

These might be useful too..



-frank

 

[Coomba]

Thanks for the tips.

 

[Joe in Oz]

I'm curious why you want to make them. Are they sizes, shapes or threads you can't get any more?
Modern machine screws have rolled threads and are significantly stronger than cut thread screws of yesteryear....

 

[Coomba]

They are for an old, hit, and miss engine I have been restoring. Why? because I can, and it's more fun to make them, than to buy them.