kev56 Posted January 23, 2018 Report Share Posted January 23, 2018 (edited) Question for any gunsmiths out there. I'm going to make some proper 'gun ' screw drivers, is there a basic width and thickness set of dimensions for traditional British guns. I'll be making them similar to this. Edited January 23, 2018 by kev56 Quote Link to comment Share on other sites More sharing options...
buze Posted January 23, 2018 Report Share Posted January 23, 2018 If you are making some, I'd be interested in a set. I don't think there are any standard sizes, by inspecting 'classic' guns I have. You can 'make do' with a couple for most screws, appart from the 'big ***' ones -- so yes I think a set of 3, 4 max would be enough in most cases. I've seen at least one gun with 'upgraded screws' where the slots was re-cut slightly wider, and allows a 'modern' screwdriver to do the job too.. Quote Link to comment Share on other sites More sharing options...
bigman Posted January 24, 2018 Report Share Posted January 24, 2018 There called turn screws Quote Link to comment Share on other sites More sharing options...
kev56 Posted January 24, 2018 Author Report Share Posted January 24, 2018 The idea, as far as I understand about gunsmith screw drivers ‘ turn screws’ is that unlike normal screw drivers they do not taper on the point. By having a parallel / concave point they are a better fit and more friendly to the screws. I was just wondering if there was a standard slot dimension for the screws. I’ll measure up a few of the slots anyway and machine the tips to a snug fit. Then harden and temper. Quote Link to comment Share on other sites More sharing options...
bigman Posted January 24, 2018 Report Share Posted January 24, 2018 3 minutes ago, kev56 said: The idea, as far as I understand about gunsmith screw drivers ‘ turn screws’ is that unlike normal screw drivers they do not taper on the point. By having a parallel / concave point they are a better fit and more friendly to the screws. I was just wondering if there was a standard slot dimension for the screws. I’ll measure up a few of the slots anyway and machine the tips to a snug fit. Then harden and temper. Be interested to see the end result buddy , what steel you plan on using? Quote Link to comment Share on other sites More sharing options...
CaptainBeaky Posted January 24, 2018 Report Share Posted January 24, 2018 I would suggest machine to over size, heat-treat, then grind/polish down to final size Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted January 24, 2018 Report Share Posted January 24, 2018 Most if not all traditional "turnscrews" are dressed down to size for a particular "pin." That is why most Gunsmiths have lots of them. To make a set of two or three for a particular gun would be an interesting thread for the DIY Section. I love the shape and feel of that traditional handle shape. I hope to see you post some pictures of the work Kev56, I think you might get a lot of requests to supply other members on here. Quote Link to comment Share on other sites More sharing options...
matone Posted January 24, 2018 Report Share Posted January 24, 2018 The turnscrews in fitted cases are a work of art in themselves .Fine craftsmanship in anything is lovely to see. Quote Link to comment Share on other sites More sharing options...
JohnfromUK Posted January 24, 2018 Report Share Posted January 24, 2018 (edited) 2 hours ago, TIGHTCHOKE said: Most if not all traditional "turnscrews" are dressed down to size for a particular "pin." That is why most Gunsmiths have lots of them. That would be my view; I don't think there were 'standards'. Both head diameter and slot width vary. 1 hour ago, matone said: The turnscrews in fitted cases are a work of art in themselves .Fine craftsmanship in anything is lovely to see. They are nice to see - but often completely useless; my Beretta came with a (very smart turned shaft) set - and they won't fit a single screw on the gun as the blades are (much) too wide for the (very narrow) slots! They are for show, not use. Brownells do some quite passable interchangeable bits for 1/4" hex drivers - in a wide range of blade widths and thicknesses - hollow ground to give parallel sides at the tip and decently hard, but not brittle. However - to get an extensive set is expensive .......... and the 'thin' bits needed for guns like Berettas are 'add ons'. https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-sets/magna-tip-super-sets--prod417.aspx and https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-bit-sets/magna-tip-thin-bit-set-prod44342.aspx Edited January 24, 2018 by JohnfromUK Quote Link to comment Share on other sites More sharing options...
Penelope Posted January 24, 2018 Report Share Posted January 24, 2018 9 hours ago, buze said: If you are making some, I'd be interested in a set. I don't think there are any standard sizes, by inspecting 'classic' guns I have. You can 'make do' with a couple for most screws, appart from the 'big ***' ones -- so yes I think a set of 3, 4 max would be enough in most cases. I've seen at least one gun with 'upgraded screws' where the slots was re-cut slightly wider, and allows a 'modern' screwdriver to do the job too.. These might be of interest. https://www.williampowell.com/gunroom/shooting-accessories/gun-care--cleaning/gunsmiths-turnscrews---hollow-ground_gc602 https://www.williampowell.com/gunroom/shooting-accessories/gun-care--cleaning/gunsmiths-turnscrews---flat-ground_gc601 https://www.williampowell.com/gunroom/shooting-accessories/gun-care--cleaning/deluxe-gunsmiths-turnscrews_gc603 https://www.williampowell.com/gunroom/shooting-accessories/gun-care--cleaning/interlocking-turnscrews---pocket-size_gc604 Quote Link to comment Share on other sites More sharing options...
Gunman Posted January 24, 2018 Report Share Posted January 24, 2018 Never made "turn screws" but made most of my own screw drivers for a long time . Commercial ones seemed to be in 3 sizes . That aside I must have had at least 10 screw drivers of differing sizes on my bench , all of which were hollow ground . It was frequent that a blade had to be ground to fit an individual pin, screw , nail . In later years and being lazy I just ground up good quality commercial ones ,like Snap on , for normal use , but still made my own as I like big handles for things like breech pins where a lot of grip was needed . If you are making a set for an specific gun then grind them for the slots you have .Biggest problem you may have is getting the temper right for blades ground for very narrow slots , unfortunately some of the commercial ones available are not really suitable for regular use more for decoration and it is very easy to damage a screw head with a blade that brakes in use. Best oh luck . Quote Link to comment Share on other sites More sharing options...
matone Posted January 24, 2018 Report Share Posted January 24, 2018 4 hours ago, JohnfromUK said: That would be my view; I don't think there were 'standards'. Both head diameter and slot width vary. They are nice to see - but often completely useless; my Beretta came with a (very smart turned shaft) set - and they won't fit a single screw on the gun as the blades are (much) too wide for the (very narrow) slots! They are for show, not use. Brownells do some quite passable interchangeable bits for 1/4" hex drivers - in a wide range of blade widths and thicknesses - hollow ground to give parallel sides at the tip and decently hard, but not brittle. However - to get an extensive set is expensive .......... and the 'thin' bits needed for guns like Berettas are 'add ons'. https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-sets/magna-tip-super-sets--prod417.aspx and https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-bit-sets/magna-tip-thin-bit-set-prod44342.aspx I have a set made by Chapman in USA which are very good.The bits were easy enough to shape to fit narrow slots ,even down to Purdey size . Quote Link to comment Share on other sites More sharing options...
Mr.C Posted January 24, 2018 Report Share Posted January 24, 2018 3 hours ago, Gunman said: Biggest problem you may have is getting the temper right for blades ground for very narrow slots , Best oh luck . That was going to be my next question. I have no problem making the blades handles ferrules but am not sure about the temper. Left the last one I made blue just so it didn't crack and stab a gouge in a nice freshly finished stock. It ended up almost slipping out as it twisted nipping up the "screw" under the top lever. Quote Link to comment Share on other sites More sharing options...
Gordon R Posted January 24, 2018 Report Share Posted January 24, 2018 The photo at the top has a point which appears to taper. I thought that gunsmithing screwdrivers tapered, then became even for the last couple of millimetres. There are so many different sizes on various makes, having just one set to cover all would seem difficult. I use a Snap On T-handle ratchet screwdriver with Irwin (USA) bits. Quote Link to comment Share on other sites More sharing options...
CharlesP Posted January 24, 2018 Report Share Posted January 24, 2018 If you make them like the one in the photo it might be a good idea to make the business end flat and true without the "rounding off" so evident in the picture Quote Link to comment Share on other sites More sharing options...
kev56 Posted January 25, 2018 Author Report Share Posted January 25, 2018 As i've got several (English) guns and a couple of American using the imperial system, i assumed wrongly there would be a standard screw size. As said before there are many different widths and slot sizes. I've measured up the slots and some are within in a few thou. of each other so i wont have to make too many. I've striped down a few guns for refurbish and have ruined a couple of screws that were very difficult to remove, hence the reason for making a 'proper fit' turn screw for each size. Looking at the stock photo the rounding off on the tip i think looks to me to be over polished. I'll prob use flat stock silver steel mill to shape, point width and depth. machine the tangs and heat fit into a decent file handle. Harden and temper. Quote Link to comment Share on other sites More sharing options...
figgy Posted January 25, 2018 Report Share Posted January 25, 2018 (edited) Every turn screw I’ve seen is wedge shaped and required a good push into the slot to grip before turning. This way it gripped and applied force along the the full contact face of the turnscrew blade. A hollow grind will only contact a small area on each corner as it’s turned as can cause damage to the slot. If your going to grind down a screwdriver or bit to fitdonit on a diamond whetting stone or similar cold way no need to retemper as you haven’t altrered it through heating it up grinding it. Edited January 25, 2018 by figgy Quote Link to comment Share on other sites More sharing options...
JohnfromUK Posted January 26, 2018 Report Share Posted January 26, 2018 (edited) 3 hours ago, figgy said: A hollow grind will only contact a small area on each corner as it’s turned as can cause damage to the slot. Not if it is the correct blade thickness. The slot in the screw is (originally) made parallel sided - and the driver should fit snugly to spread the load over as much surface as possible. Wedge shape will only contact at the top, and will widen the slot by putting all the pressure at the top. The blade must fill the slot over the whole width AND DEPTH to spread the loads and avoid deformation. Agree that the re-tempering is the hardest part to get right, especially on thin blades. Heat treatment is a 'black art' and needs skill and experience (as well as the right material) to do well. Edited January 26, 2018 by JohnfromUK Quote Link to comment Share on other sites More sharing options...
Ricko Posted January 26, 2018 Report Share Posted January 26, 2018 Ive been picking up old wooden handled screwdrivers for a few years now and adapting them for light gunsmith work. Strip and oil/wax the handles and give the shaft a good wire brushing / light going over with 800g wet and dry. I must admit I want to practice making the ends into 'parallel tips' but just need a bit more patience! Quote Link to comment Share on other sites More sharing options...
demonwolf444 Posted February 2, 2018 Report Share Posted February 2, 2018 There are a lot of variations on gun screws, You tend to find that mass produced guns have a slightly wider parallel sided slot with parallel sides to the nail heads which fit to a flat bottomed countersunk hole in the corresponding metalwork. For such screws you need a turnscrew with entirely parallel blade and edges to fit the screw. Those such as offered by Grace USA will fit many of the modern produced guns. Because of the difficulty in grinding the sort of tips on those grace USA turnscrews ( if you are not familiar they are basically like a normal slotted screw driver where the last 1/8th of an inch is truly parallel) then to adapt normal drivers to the job the only way is to hollow grind them, so that the last bit of the turnscrew is parallel you have to be carefull not to remove the temper, or you will find that they will bend or crack. On mass produced guns you tend to find that the slots are uniform and more like the slots of a conventional slotted screw. ( Image below of the grace USA turnscrews ) ON artisan produced stuff the story is a bit different, the slots vary wildly in depth, width, profile, and they are often not truly parallel as in the image above, this image taken in my workshop shows that this slot has a slight taper, the turnscrew must be found or ground to fit. The blade is the full width of the slot, full depth and in contact at both sides of the slot. The corners of the tip of the turnscrew have been knocked off to stop the turnscrew galling the metalwork of the countersink. I make up turnscrews for the workshop from time to time, i have a few blades which fit in to a traditional bit and brace which help give extra leverage on stubborn screws, welding a nut to the shank of a turnscrew below the handle is also sometimes helpfull, it allows you to keep downwards pressure on the screw while using a spanner for additional leverage, this technique is best reserved over a week of warming and cooling and applying a penetrating oil, eventually even the most siezed screws will back out, with no damage to the slot as long as one is careful. I tend to find that if it doesn't come out after ten days of encouragement the head of the screw will probably split or fracture, in which case you have the horrible job of jigging whatever it is up and drilling down the shank without damaging surrounding wood or metal. Below is a set of turnscrews i made up a while ago and are in daily use. The handles are walnut off cuts from stock work the blades are made from landrover leaf spring - Only one fitted in the picture. I use a milenicut file to remove all the rust and scale from the leaf spring once the blade shape is cut out. the tip is marked out and filed down and left massively oversize, the turnscrews have different widths, when something new turns up another "blank turnscrew" is picked up from my box, the one with a tip near the right size selected, and ground down to fit a particular screw. If anyone would like me to make them any turnscrews get in touch best supplied over size for you to fit to your screws as needed. To me they are functional tools but when im putting time into turning and filing and grinding, and since i have to look at them on my workbench, its nice if they can be a bit pretty! Quote Link to comment Share on other sites More sharing options...
JohnfromUK Posted February 2, 2018 Report Share Posted February 2, 2018 Demonwolf, Thank you for a very interesting and informative post - and the trouble taken in illustrating it well. As they say - a picture is worth a thousand words. I have found the Magnatec bits (1/4" hex) from Brownells to be pretty good and there is a huge selection available as a starting point, especially very thin forms which are very hard to get right without spoiling the temper/hardness. If they are 'nearly right', final adjustment can be done by hand on an oilstone, removing risk to the temper. Quote Link to comment Share on other sites More sharing options...
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