[mike newall]

Doing the heater flap.

Match drilled, dimpled, found the stainless rivets......

Now - countersink the stainless hinge - Hmmmmm.

Any tips for that ? Normal countersink ? what speed ?

Thanks

 

[Vakashi]

I just carried on as per normal instructions as if it was aluminium. I didn’t even think about it. I always use a lubricant like Boelube with anything steel though. Same with the rivets. They squeezed just like aluminium. For my setup, and I stress for my setup, I have found that the slowest speed on my drill press 335 rpm and quite a high feed rate reduce the chances of chattering when machine countersinking.

 

[vernon smith]

The more flutes the more chatter, too much engagement. If you are using a drill press (as you should be with steel) run slow and use the single flute (round hole through the counter sink) and you will get a very nice result. If you use the four flute countersinks with a drill press and lock everything down tight you will be OK. If you try to free hand a four flute you will never get good results.

 

[mike newall]

Great - about to walk out to the shop.....

 

[mike newall]

Tried a test on a spare piece of hinge - used the single hole countersink cutter at 500rpm with general purpose cutting fluid and a reasonable amount of pressure.

All went extremely well, the countersinks cut well, just eyeballed the depth as the cutter wasn't in a cage.

Numatx riveter needed a little extra pressure but set the stainless rivets beautifully.

Thanks for the input chaps.