What is this gear? cutter for?

[PekkaNF]

I have got two mystery milling cutters with a bunch of slitting saws.

They look like a involute gear cutter, but shape is a bit unusual to me and markings don't look familiar. Also tooth flanks look straight - like for rack cutting.

One has markkings:
1 (number "1" alone by slot, one tooth opposite of it has a delibrate nick on the back). Rack?
900 7812 ( could be a material code?)
Schuler (Maker/Brand?)
N12
67x3,3/1,0x22 (67=diameter in mm, 3,3=root thickness in mm, 1,0=what? module? 22=diameter of the hole)
HSSE5Co. (this I know!)
Spanw 8° (Wing span

If everything fails I can still play ninja with it.

Pekka

[mhh]

More looks like a special ground cutter, 900 7812 could be the customer code or drawing number.
If it is a gear cutter it looks like it is ground the wrong way, but is is just a guess! 

[Stilldrillin]

They look like very well used/ reground spline cutters to me.

I wouldn't like to risk those teeth, on a full depth pass....... 

David D

[John Stevenson]

Gear cutters and spline cutters must be reground with the front face radially to keep the profile,
these are hooked and probably for some soft material. Also well worn and with the info given which isn't understandable you were right the first time in thinking they are throwing stars.

Try next doors cat.

John S.

[PekkaNF]

I have had these for years, I have really no idea what these are for. More I look at them, more convinced I am that they are a gruel joke someone on the tool grinding department did for a late night entertainment.

I just barely could vision acme type thread milling on butter, this cutter inclined according to a helix angle, but I can't figure out why.

This 8° markking is the one buggs me most. Can't be any real gear pressure angle or such? Could be thread helix? I should measure if it a taper of the teeth.

There are way too many cats that their owners have abandoned out for a night, but I still doubt I would take an aim at them. I't funny how there are no hordes of horny wippets roaming on night streets. And even more importantly doggs don't climb on the trees all the time and take their residence in making racket all night.

Pekka

[jgroom]

Looks like they were reground for a special job so I'm guessing the original markings have nothing to do with the current tooth profile.  I'd keep 'em in the back of the drawer.  You never know when you might need a strange cutter. 

Cheers

Jeff