To make an adjustment on a sxs, I need a fine tip screw driver with a U cut out of it. I took a piece of spring stock and cut it appropriately but now I assume I need to harden it? Any tips or advice?

It appears from the lack of information as to size of the turnscrew you require, the task at hand and your apparent lack of knowledge in hardening and tempering steel, you need a set of turnscrews made of the proper steel that you can cut to the shape you need and heat treat easy enough if required. If you search the web you can find the information you need on heat treating steel and specifically turnscrews.

All "spring" steel is not created equally.

These turnscrews are excellent and widely used for the tasks I suspect you are planning to tackle and will last you for your lifetime: https://www.amazon.com/Crown-185X-Cabinet-Screwdrivers-6-Pack/dp/B00EC99Z2O

I have some like those made by greenly they have oval shaped handle you can shoten them and file a new end

I agree with bushveld about all "spring steels" not being equal. I feel you would be better off modifying a good quality screwdriver bit by slowly grinding it to the required shape without over-heating it and drawing the temper. If you temper too soft, the bit may twist and deform and damage the screw slot. If you temper it too hard and brittle, it may suddenly break, and cause you to gouge or scratch the surface surrounding your screw. A thin screw slot requires a thin well fitted blade which is more easily broken, and increases the chances of bad things happening. So start with good penetrating oil to help things get moving.

You might also check if Brownell's or Wheeler has magnetic tip individual bits that are close to your needs. My own set of Wheeler bits seem to be a little on the brittle side, and I have had some break on stubborn screws.

Those Crown Cabinet screwdrivers from Amazon do not appear to be hollow ground, and if so, would be unsuitable for most gun work without modification.

I had a similar problem and just cut a slot in a Brownells bit with a Dremel cut off wheel. The result was not elegant but worked for my application.

I started as some have suggested, grinding a slot in a Brownells tip from their gunsmith set, but couldn't get a deep enough U. Remembered I had spring steel and have cut desired shape and hardened. We'll see if it works.

You are correct that these Crown cabinet makers screwdrivers are not hollow ground. However, they have such outstanding build quality, handle form and alloy steel that they can be made into outstanding screwdrivers for a gunsmith, and this is the reason that you will see them on the benches of gunmakers here in the USA, UK and Europe.

Firstly, you will notice how long the steel shaft is on the screwdrivers-- which allows for heat treating the tips without damaging the handles from heat after the tips are shaped according to how the gunsmith/gunmaker wants them. Secondly, and very important the handle as Mark has stated is oval shaped which allows the hand to grip the handle with great leverage in removing tight screws. Thirdly, you will see that the top of the steel shaft where it meets the wooden handle has a flat, this flat is just perfect for placing an adjustable "Crescent" type wrench to assist in removing those impossible to remove screws by turning the screw drive blade with both its handle and the adjustable wrench at the the same time.

I have two sets of these Crown cabinet makers screwdrivers. One set that I have ground and re-heat treated in the traditional gunmakers shapes; and a second set that I left unchanged. The heat treating of the steel on these screwdrivers is simple and the tempering I have found should be drawn to a light brown colour. For those of you who have somewhat limited experience of how to judge the correct colour of "cherry red" (a term that is anything but correct in telling someone at what colour to quench steel) just heat about 1 inch of the bottom (don't overheat and do not hurry the heating as you do not want to "burn" the steel) of the screwdriver shaft to where a magnet will not longer adhere to the tip and then quench it in oil---I use 5W20 Mobil synthetic oil or peanut oil heated to about 100 degrees F as a quenching liquid. (Peanut oil is wonderful medium for spring making due to its high flash temp) Then polish the tip (400 -600 grit emery cloth is good) that you have just hardened and apply heat with a low flame from a propane torch about 1 inch back from the tip of the screwdriver and and watch the tip color change as the heat progress from the flame to the end tip. When the tip changes colour from dark straw to light brown, quench in the oil.

While we are in this discussion about screwdrivers you should note that our ideas here in North America of how a gunmakers turnscrew or screwdriver's tip should be shaped is not universal. I noticed this decades ago while I was working in England and visited gunmakers shops and looked at their screwdrivers. I had also noticed that Jack Rowe made his turnscrew tips in a shape not hollow ground. For those of you who have a copy of the video "iNSIDE HOLLAND & HOLLAND" look at the shape of the turnscrews that the gunmakers are using in that video. I have not ever visited an Italian gunmakers shop, but I suspect their turnscrews are shaped peculiar to us since they use such narrow screw slots. Bottom line is I have some turnscrews/screwdrivers shaped as Jack Rowe did his and some shaped hollow ground.

Further to the "hollow ground" of the tip. If one thinks of the perfect way to hollow ground a turnscrew or screwdriver tip (according to good engineering and machine shop principles, it seems to my way of thinking that the perfect hollow ground shape should be wider by about .003" to .004" at the very tip for a length of about .010" to .012". If ground this shape when one exerts rotation of the screwdriver in the slot of the screw, then the wider bottom of the tip does not allow the screw slot top to be "buggered" as long as you do not allow the screwdriver to slip. I have seen few people pay close attention to grinding screwdriver tips and correctly heat treating them.

Stephen Howell

I have brownells thin bit set and they need to be annealed .i learned to file up my screw drivers from Len bull and Jack Rowe you can use a grind wheel in a drill press at slow speed to shape the tip of your tool.

I have ruined every screw driver I have ever tried to shape. I have purchased many different sets from all the reputable warehouses and with the last set from Brownells I actually got a set that I can use for general gun work, no serious smithing or any other work of course. I will leave that to and actual gun smith who I will willingly pay to have the correct tools!!

go with modern out of the box guns, all you'll need is a punch pin set!! LOL!!!!

I use a 1” diamond wheel in my drill press to reshape screwdrivers. Perfect radius for holllow grinding and for some reason doesn’t heat up the metal as a stone will. And I use a small machinist vice purchased on eBay to clamp the screwdriver in. Grind one side and flip the vice over and grind the other side. The result is a driver with perfectly parallel sides.

Joe;

You are very correct 1 inch is an excellent size diameter to shape screwdrivers and the point you make about the diamond one is spot on.

As to the equipment to grind the shape of the hollow grind tip, the mini mill/drill is top notch and worth the money if you only were to use it for that task alone as you can mount your screwdriver in a milling vice and not have to move it to grind parallel sides. I have had mine for so many decades that they only cost $200.00 then if that much. There are dozens of things you can do on these little wonder drill/mills in repairing guns. Many people think the asian made mini mills and lathes are a piece of junk, but they are excellent for small tasks where you only need thousands of an inch accuracy vs. ten thousands of a inch accuracy. Of course a skilled machinist can take a worn out South Bend lathe that is 80 years old and produce very accurate work. I am using my mini drill/mill today as I make a barrel wall thickness gauge. https://www.grizzly.com/products/gr...02em48wIVja_ICh0A_AmrEAAYASAAEgJai_D_BwE

Screwdrivers for those very narrow slots in the end after some use I found that they would eventually twist or break. so a long time ago I started to make my own but found that re purposing screwdrivers I in second hand shops and later car boot sales. The main problem a lot of folks find with re grinding screwdrivers for thin slots it was rather difficult not to draw the metals temper ending up with a soft blade. There is a grinder that is more akin to wood working though I now would not be without one though I am not suggesting that you rush out and purchase one but if you are a practical type of person you would wonder why you never purchased one a lot earlier. I am talking of a standard four inch fast grind er with a fast dry stone located at one end and a wet grind stone at the other, Ideal for sharpening hand plane blades and wood chisels to knives and scissors and everything in between. The water stone stops drawing the temper from the steel no matter how thin you grind it to so ideal for hollow grinding screwdrivers. I found that after rough grinding lathe tools from HSS blanks a quick touch up of the cutting edge on the wet stone I could skip the oil stone honing of the cutting edge, the one in the picture is a standard hobby type not a lot of money I have had one for a lot of years now replacing each stone twice for the wet and four times the fast stone.




The picture is a stock one but they all look the same also the cost of the grinder can vary dramatically depending what name is on the thing.