Specialist hand tool: 3/16" 4-point socket

I’m looking for a tool to turn some 3/16" square-headed bolts.

I think the ideal would be a socket which I could use with my existing 1/4" drive ratchets, extensions, etc. It’d have to be a 4-point or 8-point socket, and that non-standard point count has been impossible to find.

Something like a t-wrench would work also. I found this Loading..., but I’d prefer not paying $25 for something I can’t get a picture of, at least until I’ve exhausted the other possibilities. At the obvious end, Sears’ Craftsman line has 8-point sockets down to 1/4", but not 3/16".

I need more torque than a nutdriver can supply. Given the small fastener size, we’re not talking 50 ft-lbs here, but it’s also not hobby stuff; I need to be able to apply real force. And due to the geometry, a plain 3/16" open-end or box wrench doesn’t have room to swing freely.

Anyone with better knowledge of hand tool suppliers (or better Google-fu) care to take a crack at this? Thanks in advance …

McMaster-Carr is your friend.:wink:

twelve point sockets will work on square headed bolts as well. Might have to test fit a few to get it I suppose.

What are you working on?

I know you said that a wrench will not swing clearly, but perhaps a carburetor wrench would. Mine are Craftsman and are very well machined and strong. And short. Maybe the swing won’t be a problem.

They come in a set. Pretty much any and all sizes from 3/8" down.

Fap fap fap.

sorry. i love tools.

If it’s a twelve point triple square, with 90° point angles, it will work fine. If it’s the much more common twelve point double hex, with 120° point angles, it won’t fit well and may not work if the fastener is very tight.

How long a reach do you need? An autoharp/zither/hammered dulcimer tuning wrench will reach down a couple inches. I would expect these to be in stock at any music store that sells the relevant instruments.

See, I just knew you made that up, but there it is in your link, in all it’s glory. :dubious:

It was more fun to think you just made that name up.

They make a universal socket that is designed to grab any worn bolt. The overall size is about like a 13/16 socket if you have that much room. The mechanism consists of pins that depress into the socket when you push is over the bolt. The remaining, un-depressed pins then lock and grab the bolt on the side. One brand is called Gator Grips Universal and sells for $9.99.
Available at Sears: http://www.sears.com/shc/s/p_10153_12605_00947078000P?vName=Tools&cName=Auto&MechanicsTools&sName=Sockets&sid=IDx20070921x00003a&ci_src=14110944&ci_sku=00947078000P

Also from K-Tool

Thanks all. McMaster-Carr was the answer. I shoulda checked there first. D’oh for me.

FYI GaryT, those tuning hammers are generally crap. The main issue is that autoharps, dulcimers, and similar stringed instruments use a tuning pin called a “zither pin”. These pins come in several almost identical sizes from different manufacturers, and worst of all the design is a tapered square cross section swaged onto a round pin. No two pin maunfacturers use the same taper, or deck heght, nor even min & max cross section.

So the typical tuning hammer is made like a cheap chinese screwdriver; sorta universal in that *barely works on most things, works well on no things *fashion.

The tuning hammers sport a more or less square hole, more or less tapered. It will fit over any given manufactuere’s tapered pin sorta and may or may not bottom before it fully engages the flats.
In fact this is for tuning a harp. A harp with real “harp pins” which are different from zither pins in that they have a true square head without tapered sides. Thereby enabling the use of real tools. Miraculously, the pins on this particular harp are even manufactured to the same size standard as 3/16th bolts, not some odd size neither metric nor USSAE. As we’ve found on many other harps.

As an engineer looking at musicians’ & instrument maker’s work I am continually amazed at how so much craftsmanship can be coupled to such lousy industrial engineering. Standardized fastener sizes with real & reliable tolerances have been out for, oh, two and a half centuries now. Time to get with the program people.

Thanks to all who contributed.

And for the really hard to find:
Use a socket that is just too big.
Coat the ‘nut’ part in vasalene.
Fill socket with liquid steel or JB weld.
Wait, then dress to suit with drimel tool.
You can even repair a spun out auto engine crank pully with a key way if it is out of production.

If you’re really desperate, get your open end wrench, and put it on the nut VERTICALLY. Then use an adjustable wrench on the handle of the first to provide the twisting force to crank 'er around.

Not exactly a safe or proper use of tools, but if there’s no choice in a situation. there ya go. Just be careful!

Hi. Just dropping in to say thanks very much! :slight_smile:

I’ve got a 3/16" square bleed screw in a domestic radiator with the corners rounded off due to badly-fitting keys, so I’m hoping this will get me out of having to replace the whole rad. :eek:

Can’t find anything like this here in the UK - hopefully McMaster Carr can ship here