Need help ID'ing these bars and collars

[Robert Shimko]

These bars came with my 1939 South Bend 9" Workshop lathe.
They are 5"s long and 1/2" diameter. One bar is stamped on the end with a shield and the words STANDARD 8616.
the other is stamped 1/2" STANDARD TOOL CO. and 52941. Both bars measure .504 on one end and .500 on the other. they are center drilled on each end.
The three collars are all approximately 1" long (one is dead on the othere are 1.007 and 1.016) One collar has a .438 bore and the slot is .062 dp.
The second collar has a .3125 bore and a slot .140 dp. The last collar has a .250 bore and a .175 dp slot.

 

[JimDawson]

The small ones are bushings for using smaller shank tool bits in larger holders. Example, 1/4'' shank endmill in a 1/2'' holder. Common on old Atlas mills, and maybe lathes.

The larger ones are tapered arbors for holding parts while turning.

 

[RJSakowski]

The collars look like the ones I have to reduce the diameter of a boring bar. The clamping set screw goes through the slot to contact the smaller boring bar and lock it in place.

wedit: Darn, you're just too quick on the type, Jim

 

[Robert Shimko]

Thanks for the replies, I can see the sleeves used as bushings.
I was hoping that the bars could be used asheadstock to tailstock alignment bars, but I dont thhink they are precise enough.
Thanks again

 

[craptain]

The bars are actually arbors for turning between centers. The bar is pressed into the bore of the work firmly enough to maintain the drive friction for turning. I press them in with my arbor press.
The flat section is where you attach the drive dog.

Sent from my SM-G930T using Tapatalk

 

[Robert Shimko]

Thanks again, they may com in handy!