Timothy Miller Posted September 21, 2012 Share Posted September 21, 2012 I am cleaning up the shop and orginizing my cutting tools. I found these taps in the corner I bought these at a estate sale form a person who was "Machine Fabracator". Most of the stuff was WW2 era type stuff. Though there was older stuff there too. These all have #2 morse taper shanks. The the taps are not tapered at all. Quote Link to comment Share on other sites More sharing options...
John B Posted September 21, 2012 Share Posted September 21, 2012 They look similar to what were used for threading pipe fittings, used on machines with reversible motors. Others may know more specifics or have alternative suggestions Quote Link to comment Share on other sites More sharing options...
RGraff Posted September 21, 2012 Share Posted September 21, 2012 Look like bottom taps to me. No taper allows the user to get threads to or very near to the bottom of a blind hole. Optimizes the amount of bolt or screw you can get in the material. Not sure about the pipe thread thing. I'm not a plumber or fitter but I believe a pipe thread is tapered for it's full length, aiding in the sealing of the joint as the two pieces are tightened. Someone with more knowledge than I please jump in. This season,could you want to be a fashionable person, what kind of pattern shoes is necessary to be choiced? A variety of complete material splicing and creative fantasy splicing plan for shoes is Christian louboutin ,are you Cardiac? now action,look for your love shoes in Christianlouboutingoods.com Quote Link to comment Share on other sites More sharing options...
John B Posted September 21, 2012 Share Posted September 21, 2012 (edited) Not sure about the pipe thread thing. I'm not a plumber or fitter but I believe a pipe thread is tapered for it's full length, aiding in the sealing of the joint as the two pieces are tightened. Someone with more knowledge than I please jump in. Internal threads are parallel, the external tapered thread produces the seal, or vica versa depending on situation You can get tapered taps and dies or parallel ones, and die nuts Edited September 21, 2012 by John B Quote Link to comment Share on other sites More sharing options...
petere76 Posted September 21, 2012 Share Posted September 21, 2012 They are bottoming taps. Machine thread. Tapered threads are for pipe (NPT). Straight threads are machine screw (NF) (NC). Count the TPI and determine if they are fine or coarse and refer to a drilltap chart. Taps usually come 3 to a set; starting, tapered and bottoming. Bottoming taps are used on blind holes after you start the hole with the previous two taps. Yours have a Morse tapered (MT) head and probably went into a power drive of sorts. Peter Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted September 21, 2012 Author Share Posted September 21, 2012 The two shorter ones are marked .900-20 the large one is 1.100 -20 the other one is 24 threads per inch and measures about .985 . What ever they are for is something very specific. They do not match any threads on my thread chart. I checked pipe, fractional and metric sizes. Quote Link to comment Share on other sites More sharing options...
r smith Posted September 21, 2012 Share Posted September 21, 2012 Internal threads are parallel, the external tapered thread produces the seal, In USA NPT pipe threads are tapered inside and out, they are most common. I think BSP? are straight though. American pipe sizes can also be had in straight pipe. IIRC it is called NPS Everyone is right in this case due to differences over the globe :D Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted September 21, 2012 Author Share Posted September 21, 2012 In USA NPT pipe threads are tapered inside and out, they are most common. I think BSP? are straight though. American pipe sizes can also be had in straight pipe. IIRC it is called NPS Everyone is right in this case due to differences over the globe :DYea but what are these taps Quote Link to comment Share on other sites More sharing options...
r smith Posted September 21, 2012 Share Posted September 21, 2012 Oh yea, me thinks they might be for threading holes? :P Quote Link to comment Share on other sites More sharing options...
John B Posted September 21, 2012 Share Posted September 21, 2012 Yea but what are these taps The two shorter ones are marked .900-20 the large one is 1.100 -20 the other one is 24 threads per inch and measures about .985 . What ever they are for is something very specific. They do not match any threads on my thread chart. I checked pipe, fractional and metric sizes. I would think the first number is the outside diameter of the thread, and the second is the teeth per inch, With a relatively fine pitch like that I would think along the lines of brass fittings for lighting systems, or for bicycle fittings (spoked wheel hub maybe?). or at those sizes, they could be used for caps on machinery grease/oiler reservoirs. In the UK 24 tpi used to be a brass thread used on light fittings, and covered a range of different diameters, but with the same tpi I would like to add that here in the UK we also had Taper taps and dies for internal and external threads, they were BSPT, and also some BSPNT memories a little fuzzy now and most were sold off in job lots at auction when I retired, but they also dated to about the same era as those you are showing Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted September 21, 2012 Share Posted September 21, 2012 When I was working in a couple of gun shops we had some big taps like this but I can't remember what if ever I used them for, they were just there in the rack behind the lathe in one of the shops. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted September 21, 2012 Share Posted September 21, 2012 I bet since they don't match your charts they were for a specific set of tasks. Morris tapers are on a lot of larger drilling machines, so they are not limited to use in a lathe. Metric approximations? 1.100 x 20 = 27.94 M 1.27 Phil Quote Link to comment Share on other sites More sharing options...
John B Posted September 21, 2012 Share Posted September 21, 2012 Hi Phil, Is a Morris taper the same as a Morse taper? Quote Link to comment Share on other sites More sharing options...
pkrankow Posted September 21, 2012 Share Posted September 21, 2012 Hi Phil, Is a Morris taper the same as a Morse taper? My bad spelling causing confusion...Yes, Morse taper. I know that at school and in a shop I worked in for a summer the lathe tools would be switched into the drill press(es) without difficulties, that is bits, Jacobs chucks, These were larger drill presses, speed, feed, brake, reverse... At school tapping was done using the drill press. Typically the hole would be drilled, then tapped without changing the setup. (I was only allowed to operate the machines at school though) Phil Quote Link to comment Share on other sites More sharing options...
MOblacksmith0530 Posted September 21, 2012 Share Posted September 21, 2012 Those are most definitely bottoming taps. and rather large ones at that. I think you don't have a need for them and should ship them to me so I can use and admire them.... I will even pay shipping...... Seriously like was said before you would use them to tap the bottom of a hole to get the most thread if you couldn't get the depth you wanted. I use them all the time. I have even taken a standard tapered tap and turned it into a bottom tap by slowly grinding it flat. You tap the hole with a standard taper tap until it bottoms out and then finish it with a bottom tap. I just did one on a piece I had to have a threaded stud that held a bar on where I couldnt go to deep. Quote Link to comment Share on other sites More sharing options...
ciladog Posted September 22, 2012 Share Posted September 22, 2012 Tim, They look to be left handed taps. Hard to tell for sure from the pictures. Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted September 22, 2012 Share Posted September 22, 2012 No telling what they were for originally. Where I work we have dozens of non standard specialty taps that we use for customer's parts. Many threads are just turned in the screwmachine via single pointing, or thread whirling. The taps were usually picked up for reworking tight threads. Not everything is, or was made with standard threads. Even today with SAE, ISO, Etc special threads are still used. Before the standards it was a free for all. I found this out doing gunsmithing. Many gun screws are very off the wall sizes, and thread pitches. This doesn't help you much, but unless you can find out what they were originally for, you have some forging/tooling stock there. Quote Link to comment Share on other sites More sharing options...
iron woodrow Posted September 22, 2012 Share Posted September 22, 2012 possibly for bicycle hubs, bottom brackets etc...? Quote Link to comment Share on other sites More sharing options...
Tom Allyn Posted September 26, 2012 Share Posted September 26, 2012 I'm think they're for tapping something like head bolts or some other high strength application. Whatever they were used for, the user was counting on all the threads taking load. Maybe holes for pressure vessel bolts? Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted September 28, 2012 Share Posted September 28, 2012 In the cycling industry alone there are tons of different threads. Std English, whitworth and BS. Std Italian (and some old MASI ). Std French, Motobecane, Frejus had some special threads. Bottom brackets and headsets are the common things in this vein but dropouts and seat pin stays also are issues. I haven't even mentioned tubing size issues. Of course there is NC ? NF here in the US plus national arbor thread(s), standard coaster and/or quick release. Schwinn had some of it's own threads in the past. So did Sears Roebuck Timothy, I hope you find the use(s) for those taps. I used to have books that told MOST various. cycling threads. That was 35 years ago. Never mind English sports cars or the Italian stuff. Good luck my friend. Morse tells me it was intended for machine use. Gun threads were mentioned and that indeed is a whole other plate of enchiladas. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.