VaughnT Posted December 15, 2012 Share Posted December 15, 2012 It seems like I'm always having to hunt down a nut to go on a bolt.... and I have no idea which thread or such I'm looking for. It's trial and error. Just noticed, for example, that the leg vise I bought doesn't have a nut on the bolt that goes through the bottom plate. It's a large bolt with coarse threads, but you can't exactly buy one of those at the store..... So, looking around on ebay, I see a lot of thread gauges for sale, and some of them are rather reasonably priced. But I don't have a clue as to which would best suit my needs. I'm working on a lot of American-made stuff from the 1900's to today, so standard threads are the norm. But.... Thoughts? Who do you like? Quote Link to comment Share on other sites More sharing options...
Frozenforge Posted December 15, 2012 Share Posted December 15, 2012 Mcmaster Carrr has many different thread pitch guage sets, American National, Metric, Whitworth, Acme. The type where you actually screw nuts or bolts onto it to identify are limited to specific bolt diameter and pitches, most times when you cant seem to find a bolt or nut that fits it ends up being a nonstandard combination of diameter and threads per inch. The thread pitch guages can be used regardless of bolt diameter. They seem to range from around $20 to $80, the acme thread guage was the most expensive. Quote Link to comment Share on other sites More sharing options...
VaughnT Posted December 15, 2012 Author Share Posted December 15, 2012 So, basically, I have to buy all of them? With my luck, I'll buy a gauge and it won't have the size I need... so I have to buy another gauge. The thread pitch gauge looks to be the ticket. Now I just have to decide which ones would best fit my needs. Quote Link to comment Share on other sites More sharing options...
Backwoods Blacksmith Posted December 15, 2012 Share Posted December 15, 2012 Get one that will measure from 32 pitch to 4 pitch. That is threads per inch. This will cover both course and fine threads of all you may encounter. Likely your vice is an acme thread. You can measure it with a tape or scale. Measure from the back of one thread to the front of the one at 1 in. Count the full threads.This will give you the TPI. Hope this helps Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted December 15, 2012 Share Posted December 15, 2012 Threads have had industrial standards for a couple hundred years but that doesn't mean every manufacturer used them. I suggest you obtain an older copy of Machinery's Handbook and read up on thread systems. That will give a good idea of what you might encounter and methods to measure them. It's also an excellent book for any metalworker to have in the library... Quote Link to comment Share on other sites More sharing options...
Bob S Posted December 15, 2012 Share Posted December 15, 2012 Go to your local fastener store (maybe Fastenal), or try your local farm/implement store if you are in a rural area. Sometimes they have a plastic, giveaway type gauge for measuring nuts and bolts. I would also get a low priced dial caliper (under $50) so that I could measure directly. http://www.use-enco.com/CGI/INPDFF?PMPAGE=297&PARTPG=INLMK32 Quote Link to comment Share on other sites More sharing options...
pjh66 Posted December 15, 2012 Share Posted December 15, 2012 I would recommend at least a set of UN thread gauges, a set of vernier calliper and some sort of thread reference book. You made need to get a set of metric gauges also. The larger range of thread pitch it covers the better. UN gauge can be used on whitworth. The difference is UN has a 60deg angle thread & whitworth is 55deg. Both are measured how many threads per inch. Metric is also 60deg but is measured millimetres per thread. If you can take the bolt out probably easier just to take it to your local fastener supplier & ask them for a nut to fit the bolt. As HWooldridge said a machinery hand book is great to have for all metal workers and there is a heap of information in it. Quote Link to comment Share on other sites More sharing options...
Ricko13 Posted December 16, 2012 Share Posted December 16, 2012 When I started as an inspector in a machine shop, the first thing mu boss at the time told me to do was read through the thread section of the mschinist handbook. The next thing he told me to do was go through a small bin of nuts and bolts and sort them using only a dial caliper. You can figure out pretty quick threads by measuring the Major diameter (over the top of the threads) and figuring out the Thread per Inch. Thread pitch gauge was also very useful to sort through metric and unified that measured close. Nuts are a bit harder, just need a few bolts to help you. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 17, 2012 Share Posted December 17, 2012 Is this the pivot bolt that the moving arm pf the postvise pivots on? If so the *old* ones didn't use a screw/nut but tapered wedge. (I've had a couple that way) A simple cross drilling and cotter pin or spring pin should do you fine as you don't want the joint pulled *tight*; you just don't want the pivot bolt to work itself out. As to matching nuts and bolts I *always* bring the piece I have to be tried with the selection at the hardware store. *especially* since with old equipment I have sometimes found different threads on the identical? bolts as a previous repair used whatever was to hand. Quote Link to comment Share on other sites More sharing options...
Francis Trez Cole Posted December 17, 2012 Share Posted December 17, 2012 many tap and die sets have a set of gagues with them. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted December 18, 2012 Share Posted December 18, 2012 Get an American and a Metric for the common profile (it is slipping my mind now the name) in the size range you are typically using. If you get into small stuff make sure there are no obvious gaps in the range (I have a set of gagues that skip 28 TPI from a tap and die set) You can measure other types of threads with the standard set, but the set specific to the thread you are measuring is better. You just line the points up with the same edge of the threads for square profiles. You can also do some creative measuring and use the half size finer to measure large thread pitches with accuracy...just be careful that you are counting the right number of points between each and every thread. Phil Quote Link to comment Share on other sites More sharing options...
EGreen Posted December 18, 2012 Share Posted December 18, 2012 I'm thinkin Starrett is the major mfg of measuring tools.and I think that is what my thread pitch gauge was Quote Link to comment Share on other sites More sharing options...
Ricko13 Posted December 19, 2012 Share Posted December 19, 2012 http://kbctools.com/usa/Navigation/NavPDF.cfm?PDFPage=714 whole page just of thread pitch gauges. Quote Link to comment Share on other sites More sharing options...
macbruce Posted December 19, 2012 Share Posted December 19, 2012 I have often used my thread files to determine thread pitch, both metric and SAE, they're handy to have anyway. Quote Link to comment Share on other sites More sharing options...
John McPherson Posted December 19, 2012 Share Posted December 19, 2012 You can buy either name brand or bargain basement stuff here: http://www.wttool.com/ They have always worked with me on getting the supplies I need. They carry a full line of tools, including all sorts of screw gauges. Quote Link to comment Share on other sites More sharing options...
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