Lathe Lead Screw Measuring

A short video to help Steve (buckrun11) in Ohio to measure his lathe lead screw pitch.

[@robertdebusk6157]

Thank you Tom, for helping a brother in need. Bob

[@littlestworkshop]

Or turn leadscrew one turn manually and measure the travel of the carriage with a dial gauge. See if fits a metric pitch and also divide into an inch to see if it is an imperial one.

[@RRINTHESHOP]

Tom, thanks again for the great video. I see many god ideas in the comments. Here is an easy one. Engage the half nut, rotate the chuck by hand a few turns to remove any backlash, make a sharpie mark on the ways, rotate the chuck and count the # of revolutions of the lead screw, then measure how far the carriage moved along the ways. Pitch is a measurement of distance traveled per revolution. Your lathe carriage travels 0.25" per rev. for a pitch of 4 TPI. Just offering another idea. Thanks again.

[@thorweldinginnovations6167]

An easy way to ID the leadscrew is to count 10 threads and measure the length in mm and compare this to how close the threads fit into 1". 10 threads of 6mm will give exactly 60mm or 4 mm threads will be 40mm. Threads will start and finish on the same place on the thread pitch. An imperial thread will start and finish at the exact same position of the thread pitch when measuring over 1" and will be off when measuring over 10 threads.

[@GaWajn]

I like it that you took time to help another person with a youtube visual. That way we can all follow the investigation. Thanks!

[@علي2024]

Sir tom i do appriciate ur efforts u got really a good experiance wish u all the best .

[@wyattoneable]

If I could hit the "like" button a thousand times I'd do it on this video for sure. It was very nice to take some time out to help Steve...and me too. I'll remember this when I get a lathe of my own.

[@oxtoolco]

Hey Wyatt, Lots of other things to click on to help out. Thanks for the positive feedback. Cheers, Tom

[@CruiserMac]

Very informative Tom, nice of you to help out a viewer.

[@swarfrat311]

Hey Tom, Good information to know, from the guy that knows! Regards, Oxen Dave

[@EVguru]

Hi Tom, The cut threads were apparently coming out OK, it's just the threading dial that's behaving strangely. The threading dial was fitted with a 15 tooth gear (meant for metric), now it has a 16 tooth. I'm beginning to wonder if the saddle isn't fitted with metric half nuts that are only partly engaging with an imperial leadscrew. I think we need to see dial gauge readings whilst the leadscrew is rotated whole turns.

[@daque1960]

Only thing I could suggest is maybe measure over a larger distance and only if you really don't know if it's English or metric.. Most dial calipers are 6" plus so maybe measure over 5 inches and divided 5 by the thread count. To check if it's metric I would switch to mm and measure threads in 100 mm the same way. Probably more work than is needed for this but averages out minor error you might get with no real point on acme threads.

[@redman007100]

Hi Tom,really enjoy ur vid's.Thank's Terrence

[@gestoriaradicacionradicaci9315]

Thank Sir for share.you knowledge

[@jusb1066]

i think its a good idea to measure more than one peak to peak, as you did, you measured 4, he may want to measure 10 perhaps, and thus gain a more accurate measure of the pitch, one can more easily lead to error

[@AmateurRedneckWorkshop]

Short and sweet huh? Still a good video and helpful to lots of people.

[@mikeadrover5173]

As always, thanks’ for taking the time to make this video! And I support this site. ~M~

[@MarkHinchey1]

Welcome back dog stools! Gotta love auto generated captions.

[@ce208b2]

the guy over at the AppliedScience channel had a similar problem on his Grizzly 4003g lathe. He has a review video of the lathe. He says that Grizzly shipped his lathe with a 15 tooth thread counting gear designed for a metric lathe and it should have been a 16 tooth gear.

[@heatherx1071]

Hey Tom I have a grizzly g4003g lathe also the lead is .864 in and I believe it is 9tpi. The thread chaser has 16 teeth. A friend of mine was having the same problem and it turned out they had installed a metric gear I think it was like 22 teeth she called them and they promptly mailed her the correct gear.

[@lesthompson5907]

hi Mr OXTOOLCO? , this question is one that need a bit of explaining i wuld love to hear your tack of the subject . I think it an interesting , subject. & as potential for grat development in the CNC Domain To , On with the suggest! , i live in England & own one of the UK School lathe's . it about 150 years old it as the ability to cut threads up to 4 treads to the inch , & as small as 50 to the inch. but it as no lead screw. & it perimetry . screwing drive . is the rack. I would love to fit a tread dial .So i no longer need to time the lathe to cut a tread ? Now the Question is wuld it be best to fit a sliding free turning Keyed sleeve as 8 thread's to the Inch Or an appropriate gear that rid on the rack tuning a Dial ? At present i ues a rotter & thread mill to cut the small threads in it appropriate gear seclusion on the banjo but single point therein still avails me as i cant start the tread consecutively in the same place without trading diel . is it possible you can cover this on a video to whach . [ Les in England] IV Raised the subject with so meny But they never Respond ?. thank you preps you will the German cheapy Stephon came up with using the third mill siystom. it work's well very well for small trad's But i won't to cut a Spindale tread for my lathe to mount a chuck plate . & wuld lick to single point thread it , we There's my problem can you help ? whit an ideal Some clarity . my drive spindle is Like a Milford Lath led screw, but with out the third my idea was to fit a sliding thread which is keyed ? & mount a diel to that ? Well their you have it what do you think ?

[@erynthegrey]

If it has a threading dial, it's should an SAE thread, right? My thought is that metric threading half-nut is never disengaged, thus renderin thread dial as unneccesary. Did he give the model of the Grizzly lathe? Should be be easy to track on the grizzly website. My lathe is Chinese and has an SAE thread lead screw and a threading dial.

[@EVguru]

Metric lathes have threading dials too! It's only the special case of cutting a non-native thread; metric with an imperial leadscrew, or imperial with metric, etc. that means the half nuts can't be disengaged without special techniques.

[@erynthegrey]

Cool. Never knew. Thanks.

[@chrisstephens6673]

Paul Compton Hi Paul, my metric Colchester Bantam has no threading dial, one would only be needed for threads that are not a factor of 6mm, as the half nuts can be engaged anywhere. For non factors, or Imp threads, a "clapper box" threading tool saves the day. ATB chris

[@thedge7]

It would be interesting to have a discussion about what features are desirable in a lathe. For instance is a larger dia. lead screw better than a smaller one? something along those lines. For prospective buyers.

[@zyzzz6331]

What type of thread is it? Square thread?

[@buddylineman]

Hey Tom, I have a grizzly G4003 lathe I don't know if I can help but I would be happy to try. Thanks for all your videos. Buddy

[@lordmcted]

heya tom, i love your videos, a lot, you're one of the best people on youtube to watch and listen to, especially the detail you go into the way i go with this, is if i set a caliper to 1 inch, and it lands even on the threads, its inch, if not, its metric i mean, if we're trying to find out if the shoe fits, just check if the shoe fits

[@oxtoolco]

+lordmcted Hi Lord, That works if all you care about is if the leadscrew is inch or metric. This video was created to help a friend that was having some difficulty determining the number of threads per inch. Thanks for the comment. Cheers, Tom

[@lordmcted]

oh right, my bad, sorry about that, i must have missed that part, i was tired and covered in oil and crud- nothing worse than a know it all who's not even on the right track, sorry again. great videos and thank you for sharing them and the time you put in, also thank you for responding to my comment. all the best, take care

[@gentharris]

Sounds more like 10 tpi to me which IS very close to 2.5 mm I have a small Grizzly lathe that is 16 tpi threading screw, the cross slide, compound and tailstock are all 20 tpi. I think that it is very unlikely that he has a metric leadscrew, unless the machine was not made for the US market?

[@katzefrau1]

Hey Thom. I have a Grizzly G4003G lathe. the lead screw is .864 inch and it is 8TPI . a friend of mine had the same problem with her Grizzly lathe and it turned out she had the wrong gear from the factory it was like 22 teeth or something and they do offer a metric lead screw. the correct gear for the G4003g for imperial measurement is 16tooth. I don't know if he has a G4003g but its the most common one so I'm hoping this will help.

[@dalescott4570]

Most of the Chinese lathes have a suffix "b" on the model number for metric leadscrew

[@gichehasimon]

Hello Tom, Thanks for you great educational videos, I bought a drilling coupling that was indicated as T48*10, its a metric threads, i need to thread a joining drop pipe for it but am not sure what kind of thread that is. hope you have ideas you can help me out. The diameter of the coupling is 60mm and thread diameter is T48mm*10

[@paulperrin2152]

Some are stamped on the lead screw

[@Muscle65car]

Also on the Grizzly 4003 you have to set compound to 59 deg on the scale not 29 deg.

[@weaponstester8976]

I thought u put the tread gauge in between the treads

[@krazziee2000]

good info , thanks

[@andregross7420]

Siege the makers of import machinery messed up the thread chasing dial on a lot of machines one time. Assembling them with a gear with one fewer teeth giving you false readings. Ben Krasnaw at Applied Scoence here on YT explains this in his grizzly 4003G lathe review.

[@keldsor]

Hi Tom ! How did you know I was going to do exactly that, because I'm going to make a thread dial for my old Stanko lathe - thx !

[@VijayKumar-vz5vb]

Hi

[@johnatonince7679]

Please help me out I'm going crazy trying to find the thread pitch on my 7x12 sunmore mini lathe leadscrew?? I see 16mm of diameter when I use my caliper and I use those SAE pitch measures for the threads and the only one that fits is 1.6 S.A.E! What is the name of the Tap or Die I'm looking for on this leadscrew???

[@RaysGarage]

Tom, Great info! If it would help, I have a Grizzly G0709 14"X40" with a 8 TPI X .875" Dia Lead Screw. Thanks, Ray

[@oxtoolco]

Hey Ray, Steve needs to work through this problem. What is the optional metric lead screw pitch? Is it shown in your manual? Cheers, Tom

[@RaysGarage]

oxtoolco Hi Tom, I checked my manual, the only option was the one that came on my lathe, (Cuts 4-112 Standard TPI and 0.1-7 Metric, 7/8" Dia 8 TPI). Not sure if Grizzly sells a lathe with a metric lead screw as an option. I would have him contact Grizzly Tech Support and tell them of the issue. Could also be a half nut, or clocking gear issue... Maybe we can cut him a new Inch lead screw as a last resort??? ATB, Ray

[@telosfd]

What going on with the lathes or the other machinery tools that made for the imperial system, how to change in metric, or no!

[@user-bw4rr4kd9n]

Awsome video, very helpfull. Can i ask please, i mesured my lead screw from my uknown lathe and it come to 6,5 pitch and 30mm(exaclty) at diameter. I am trying to find a split nut but i cant so i cannot use the lathe for cutting thread nor feeding. Any ideas how to overcome my problem? Thank you!!

[@oxtoolco]

Sorry to hear you have no split nut. You will most likely need to make a nut on another lathe. Another option would be to find a nut that fits your lead screw and somehow adapt it to reference to the carriage. Thanks for the comment. Cheers, Tom

[@black5f]

Good video. If it's a 2.5mm pitch then 10 threads will be 25mm, 10 tpi will be 25.4 which will be hard to spot measuring in the center. Carefully measure the width of the top of a peak ... on a acme thread relatively easy? Now carefully zero your digital calipers. Now measure across say 10 threads from left side of peak to right side of peak ... not the centers, it's easier than the centre. Your calipers are zeroed at the width of a peak so will automatically deduct 1/2 width at either end? 6 inch caliper you can measure across 60 threads ... the difference should be 2.4mm less if it's a metric thread 2.5 pitch (61 threads (very nearly) per 6 inches?). Or with a 6 inch rule there will be either 60 threads or 61? On medium size metric lathes, 10 or 11inch swing, 3mm pitch is very common.

[@Gottenhimfella]

I'm not sure why Tom didn't simply measure from left corner to left corner. Then there's no need either to factor in the width, or to guess the centre positions.

[@clayz1]

Count the full threads plus the two halves? Just count the spaces. Dont complicate it.

[@alhagopian2100]

Hi Tom Love your videos. Machining is new to me. I picked up a South bend fourteen lathe but it did not come with thread dial. I picked 1 up on e-bay that will fit but the gear is not right. I have a 1" 6TPI lead screw. Can you help me figure out what gear I need to make this work? Thanks Al

[@desmondallen6292]

Al Hagopian

[@MrJTJINX]

Hi Tom, how does this work for miltu start acme threads. ive just taken my old Elliott 181 Milling machine apart to look at repairing a backlash issue in its x axis. Its probably an imperial thread. Just curious as the DIY CNC plasma table i built has 16mm twin start acme threads, how do do go about measuring them - at first glance if the ends were hidden by machine mechanics, all you see is what looks like a normal acme thread.

[@Gottenhimfella]

Turn the leadscrew exactly ten turns and measure the movement of the table resulting. Divide that by ten times the pitch to get the number of starts

[@hettinger1000]

Hi Tom, I've got a 12 inch Clausing lathe that had a well worn split nut and a homemade leadscrew and I finally finished wearing the split nut out. I bought a new split nut from Clausing, but it doesn't work with the homemade leadscrew. (too tigxht) When I looked in Machinery's Handbook, the Acme threads for my size screw don't seem to exist. The Clausing one is 7/8" X 8 tpi. These are no longer available from the company. The one on my lathe didn't have the threads cut deep enough and they really don't look that good anyway. My hope was to find some 7/8" Acme allthread and make another one, but can find only 6 tpi. Is there somewhere you're aware of that might have what I need? Thanks

[@oxtoolco]

Hi Ed, Try Horspool and Romine in Oakland CA. They do all kinds of acme stuff. Thanks for the comment. Cheers, Tom

[@hettinger1000]

Thanks Tom, We also found an outfit called Green Bay something or other and they also had what we needed. $28 per ft in cut lengths of 4140 of the 7/8 x 8tpi.

[@MaulTechATV]

I think a 2.5mm pitch is the same as a 10 thread per inch. Going to be hard to figure out which one it is if so.

[@daque1960]

That's why I suggested measuring the threads in 100 MM and 5 inches, if its metric you get 40 right on the button, if its English you get 39 and a bit more. If you measure the threads in 5 inches and its 10 per inch you get 50 right on the button, if its really metric you get 50.8 or almost 51.

[@garthn2561]

MaulTechATV Measure the entire leadscrew - the more peaks included, the easier it gets - besides the counting.

[@ricardomolina8773]

Where can I get a large threaded rod like that Large enough where I can A large CNC machine to build boats

[@vrsarojcomedyvlogs]

Nice information sir I'm from india

[@jarisipilainen3875]

more acurate measure over 10 pitch. you see is it metric or inch right away.10mm its 1pitch metric. 15mm 1.5 metric 20mm 2 pitxh 25mm 2.5

[@saleemfarooqi7898]

v v good 👍

[@guilhermemassote70]

Legenda em potuguês

[@iraqresitance9663]

My greeting from iraq

[@GodsBattleAx]

This didnt say anything, if you dont have a thread gauge..

[@user-kh8pu2sr5f]

جميل

[@rocklives12]

Wouldn't be such a headache if everyone used metric 😭