Socket Head Cap Screw Identification ????

[JoeLee]

I'm going to attempt to make a spindle for my KO T&C grinder. I have one I want to copy. I'm trying to figure out what size SHCS they used to pull it into the quill.

Like this............... (hijacked picture thanks to PB)



Since the threaded end that goes into the quill is 3/8"-24 the bolt has to go through that. I'm guessing it's 1/4".

I thought I could reverse figure this by the size of the hex key the bolt uses. The SH is a 7/32" hex.
I have no idea what size hex bolt uses a 7/32" key.
A 5/16" SHCS uses a 1/4" key and a 1/4" SHCS uses a 3/16" key. It's not metric either.

Is there a bolt size in between ????? I have in the past seen a few different size hexes on the same size bolt depending on the mfg. and the age of the bolt. But I thought by now this was all standardized.

I want to make a spindle with a 3" TPF end so I can use my Sopko 1 1/4" hubs.

Here is a picture of the #5 B&S taper end. You can see that there is a threaded sleeve (3/8"-24) over the bolt end and it's silver soldered in place.
What size bolt do you think they used to go through this ??



The goal here is to make one of these...... unless I can find one.



JL.........................

[lakeside53]

SHCS are standardized now... but up to the late (?) '50's they were not and the head sizes were different. The "different" screws were in use for a long time after. What date is your machine?

I "think" the data is in the machinery handbook.

[MattiJ]

Not nearly bulletproof identification but the head looks like BSW fasteners have, ie no chamfering at all on the hex recess. Key size would match also for example 5/16BSF screw.

[Erich]

7/32 is the hex size for a 3/8 Flat head cap screw.

[JoeLee]

It's possible it's a 3/8 screw that goes through that spindle with the end turned down to 1/4" and then the 3/8" - 24 sleeve is silver soldered over it.

JL................

[JoeLee]

7/32 is the hex size for a 3/8 Flat head cap screw.

Maybe for a FHCS but not a SHCS.

JL...............

[reggie_obe]

Not nearly bulletproof identification but the head looks like BSW fasteners have, ie no chamfering at all on the hex recess. Key size would match also for example 5/16BSF screw.

What would a BSW fastener be doing on a machine designed and built in the USA? South Dakota I believe.

[JoeLee]

What would a BSW fastener be doing on a machine designed and built in the USA? South Dakota I believe.

Ive seen the SHCS heads that have no chamfering around the hex hole. I have a few in different sizes I pulled from scarp parts at one time. I also believe the head has a straight line pattern as opposed to some that have a light knurl pattern.

JL.............

[Illinoyance]

It a special screw that seems to be unique to KO Lee. Note that there is a reduced shank where it passes through the wheel adapter. The head of the bolt holds the taper in place. The shoulder on the right side pushes against the tapered adapter to extract it. I have no idea how it is assembled. I have a similar spindle setup on my KO Lee. I have seen literature on the Dumore toolpost grinders that shows a similar spindle adapter. It is a long shot but maybe a Dumore adapter might fit.

[Paul Alciatore]

This screw is not a common one and he has not removed it, which would be the obvious thing to do. So how do you know it is not a FHCS that has had it's head ground down?

Perhaps I do not understand what is being done, but if this is a shop made device, why not just use a standard size cap screw that will fit and not worry about what size the OEM used?

Or just pull that screw out and measure it.

Maybe for a FHCS but not a SHCS.

JL...............

[Beazld]

Have you seen this?

http://www.homemetalshopclub.org/library/applets/screw_data.html

[toolznthings]

Hi,
Older 5/16" SHCS also used a 7/32" allen. Probably 5/16". I have the same setup for my K.O. Lee

[Illinoyance]

Take a close look at the right side of the adapter in the photo. The shank is smaller than the thread diameter. No way that is a standard fastener. I don't think there is any way to remove it for measurement without destroying it. KO Lee may have used a standard SHCS and silver soldered a threaded sleeve to get that unique fastener.

[Arcane]

Have you seen this?

http://www.homemetalshopclub.org/lib...crew_data.html

Hey, thanks for that link!

[JoeLee]

It a special screw that seems to be unique to KO Lee. Note that there is a reduced shank where it passes through the wheel adapter. The head of the bolt holds the taper in place. The shoulder on the right side pushes against the tapered adapter to extract it. I have no idea how it is assembled. I have a similar spindle setup on my KO Lee. I have seen literature on the Dumore toolpost grinders that shows a similar spindle adapter. It is a long shot but maybe a Dumore adapter might fit.

I believe it's a 5/16" bolt. The end is turned down so the 3/8" - 24 sleeve can be slipped over it. Looking at the end of the 3/8" thread end it's silver soldered to the bolt.
Your correct on the pulling to seat and pushing to extract.

Not shure about the Dumore spindle, but the KO one pictured is a B&S #5.

JL...............