Pneumatic drill chuck screw size's? Where to get?

[carhouse]

I have 2 air drills that are missing the screw that hold on the chuck.

One is a CP788
The other one is a Sioux 1452HP

The Chicago Pneumatic I can't find the manual online at their website but found similar ones but they don't show the screw at all in the exploded view.

I found the Sioux 1452HP manual but does not shows the screw either.

Anyone know the part number for the screw for any of these drills or know what size screw?
The hole looks like they could be a little difference in the diameter but not 100% sure

 

[zkling]

What is the chuck mounting size? Those are usually standard.

 

[carhouse]

3/8-24 one was a 3/8" chuck and the other was a 1/4" chuck

 

[zkling]

IIRC 1/4-20 LH (left hand) is the standard, that might be for 1/2" chucks though.

 

[MFolks]

The screw in the center of the chuck, that holds it to the drill, may be left hand tread, as some are.....

 

[gungatim]

every drill I have taken apart or replaced the chuck on was left hand thread, but smaller than 1/4", I think someone suggested on another thread to take a piece of wood dowel and force-screw it in then back out again to measure.

 

[carhouse]

I bought 1/4-20 L.H. and they are too big so those might be somewhat standard for 1/2" chucks.

I think they might be 10-32 L.H. or a metric around that size.

 

[dutchgray]

I have seen M4, 5, 6 LH for sale over here in metric land for replacements. Most I have done have not been metric however.

 

[zkling]

I would have measured first, but. What is the minor hole diameter?

 

[Wamsutta]

Chicago Pneumatic Screw CPCA146086

The Sioux doesn't use a screw that I can see:
http://www.siouxtools.com/Manuals/ZCE449_revA.pdf