I Need Some HEP! LOL

[Bad Sport]

Just came across these items, I know the ones in the tubes are end mills I believe, but the other item in the tool roll I haven't a clue.

Can someone shed some light on the subject?

 

[jos51700]

Pilot reamers.
Edit. Typed that and then saw the screw sizes above the bit tips.

Spot face/recessed hole bores for screws.

 

[bighammer]

Looks to me like "boring bars" like what you would use on a metal lathe.

 

[Bad Sport]

And I guess I should add, how would they be used?

I noticed those end mills in the tubes were 20-25 bucks apiece.

Any idea on the cost of the others?

 

[pishta]

those look like pilot bits for enlarging holes or for drilling shoulder bolt holes

 

[Bad Sport]

those look like pilot bits for enlarging holes or for drilling shoulder bolt holes

That's kinda what I though originally, but there is no taper. Both steps are square, if you will, at the tip.

 

[Bad Sport]

Here is an end view of the Century tooling.

 

[Bad Sport]

The tool roll pieces are:

Twentieth Century Manufacturing Company
Libertyville, Ill.

And they refer to them as Superbore.

 

[gary74]

We use them to counter sink holes for cap-screws

 

[damraider]

Yep. pilot on the end should be 1/16 over the screw size and the cutter is 1/16 over the head size of as socket head cap screw .

 

[cjh]

We use them to counter sink holes for cap-screws

Yep....that's them.....the Pilot/Spigot good for when you require a spot face on and uneven surface.
Here is an example....although I modified a drill bit to do it.

 

[moe7404]

i call them counter bores.

 

[rlevs]

spot face or counter bores used to make a surface for the bolt head to set on