What are these?

[Andrew_G]

I got these in an auction lot and I'm not sure what they're for. P&W (Pratt and Whitney I presume) - some type of guages. 1/2, 5/8, 3/4, 7/8, & 1 inch. I can think of some uses for them on the lathe (checking tail stock alignment etc) but I'd like to know what they are really meant for. Anyone?

Thanks in advance


Andrew

 

[pdentrem]

Looks like mandrels for lathe and grinding operations.

 

[Jim F]

Lathe arbors. for turning parts between centers.
You will find they have a taper to them.
The end with the flat is the larger end, the flat is for the lathe dog screw.

 

[Andrew_G]

Lathe arbors. for turning parts between centers.
You will find they have a taper to them.
The end with the flat is the larger end, the flat is for the lathe dog screw.

That explains it, and fast!- I just checked and they do have a taper of 0.002" over the 4" length. I hadn't noticed that, and clearly that would have been a problem if I used them to check alignment.

I can see now that these could be useful.

Thanks!

Andrew

 

[Andrew_G]

Looks like mandrels for lathe and grinding operations.

Yes - thanks for the fast answer. This forum is a fantastic resource for hacks like me trying to figure this stuff out.

cheers

Andrew

 

[Jim F]

That explains it, and fast!- I just checked and they do have a taper of 0.002" over the 4" length. I hadn't noticed that, and clearly that would have been a problem if I used them to check alignment.

I can see now that these could be useful.

Thanks!

Andrew

I used 1 to make a bushing for a CBN wheel to fit my bench grinder.

 

[Ultradog MN]

I learned to call them mandrels.
Used between centers with a lathe dog.
I bought a bunch of them at an auction a couple of years ago - different sizes.
Not used often but very handy when you need one.
I needed to make the wheel clamps for one side of a big old grinder I rehabbed.
I roughed them out then pressed the mandrel into the bore.
Then I could face both sides of the clamps to the same plane and concentric to the bore so they are exactly balanced.

 

[mmcmdl]

Actually used on grinders also . .0005 taper per inch and hold concentricity pretty close . Not perfect , but close enough for gubment work .