I have something metal, with threads on the end. I have no idea what size the threads are but I need to buy a tap to match them. How the heck can I tell what size the threads are without buying 10 different taps? Is there some way to measure?
How do I measure thread size?
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Thread pitch gauge ... any inclination if it's metric or standard? The gauges comes in both.
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Measure the diameter and count the number of threads per inch.
+1 Thread pitch gauge. A lot of times you can find a combo gauge that you can measure thread pitch and bolt diameter.
Metric taps would read something like 1.50 x 12. First number is thread pitch, second number is bolt diameter.
Most of the time when you but a tap set, it comes with a thread pitch gauge.
Metric taps would read something like 1.50 x 12. First number is thread pitch, second number is bolt diameter.
Most of the time when you but a tap set, it comes with a thread pitch gauge.
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Make a mold with your favorite goo... dust it with baby powder or something so it releases cleanly. Bring goo mold into the hardware store & compare either with their bolts or they'll have thread comparison gizmos.
goo suggestions could be simple as flour/water/salt paste (play doh), caulk (don't stretch it), bondo, whatever.
goo suggestions could be simple as flour/water/salt paste (play doh), caulk (don't stretch it), bondo, whatever.
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I'm still for measuring the bolt diameter and counting the threads. It's fast and easy and works even with very small machine bolts if you use a magnifier.
For the picture I picked a largish 1" bolt for convenience:
I count 8 threads per inch.
1/8 = 0.125
pitch = 0.125
For the picture I picked a largish 1" bolt for convenience:
I count 8 threads per inch.
1/8 = 0.125
pitch = 0.125
Take the piece to the hardware store and see which nut fits it.
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But you'll have to saddle up the moose then, eh?
can you take the part to the store?
Based upon the question am assuming that you don't have any thread pitch gages or possibly calipers, so next best is to take the bolt to a store and match it by pitch first by seeing which other bolt threads fit it all along the length, and then checking nuts of the proper pitch pitch for the proper size.
post a picture here with a ruler showing both the (diameter) width and length of the threads and what the part is from. most threads are standard sizes so if ,for example, the diameter is 1/4 inch we know it will have a thread pitch of either 20 or 28 threads per inch. if it is 12mm then we know it will most likely be either 1.75, 1.5, or 1.25 thread pitch.
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Mori, counting the threads doesn't help if it's a metric bolt, and I've never heard the pitch expressed as a fraction on imperial hardware, it's always 1" x 8 (tpi), as it does in my tapping charts and tap and tools catalogues.
If the OP can, take the fastener to the hardware or tool shop and match it by laying it on top of the tap.
If the OP can, take the fastener to the hardware or tool shop and match it by laying it on top of the tap.
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Originally Posted By: tdi-rick
Mori, counting the threads doesn't help if it's a metric bolt, and I've never heard the pitch expressed as a fraction on imperial hardware, it's always 1" x 8 (tpi), as it does in my tapping charts and tap and tools catalogues.
If the OP can, take the fastener to the hardware or tool shop and match it by laying it on top of the tap.
The OP didn't say if it was a metric or SAE bolt.
A metric bolt has either a fine or coarse thread, and the pitch is the distance between threads in mm. ON SAE fasteners, the thread pitch per se isn't used but "threads per inch" instead.
On my bike there are bolts that are SAE and metric, and some of either go by pitch or TPI. I had the hardest time finding very specific axle nuts with a rotating locking washer that are metric but use TPI.
Mori, counting the threads doesn't help if it's a metric bolt, and I've never heard the pitch expressed as a fraction on imperial hardware, it's always 1" x 8 (tpi), as it does in my tapping charts and tap and tools catalogues.
If the OP can, take the fastener to the hardware or tool shop and match it by laying it on top of the tap.
The OP didn't say if it was a metric or SAE bolt.
A metric bolt has either a fine or coarse thread, and the pitch is the distance between threads in mm. ON SAE fasteners, the thread pitch per se isn't used but "threads per inch" instead.
On my bike there are bolts that are SAE and metric, and some of either go by pitch or TPI. I had the hardest time finding very specific axle nuts with a rotating locking washer that are metric but use TPI.
32 tpi is virtually identical to .8mm pitch - .03125" and .0315" respectively.
metric fasteners actually have 3 different pitches, course , fine and extra fine. Japanese machinery (cars, motorcycles, etc) will often use the extra fine whereas european machines will use only use fine.
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Well, Major Tom, I happen to be looking for a few brass set screws (Let's say they are really bolts, but they are not called "set bolts") in this metric size:
1.2 mm diameter, 2.4 mm long (without head), 0.2 mm pitch. Where can I find those?
1.2 mm diameter, 2.4 mm long (without head), 0.2 mm pitch. Where can I find those?
Is that fastener sitting on a slab of salmon ?? ....
Good luck! Your hobbies are too tiny!
maybe bobistheminaturefastenerguy.com
I don't usually deal with anything smaller then M6.
maybe bobistheminaturefastenerguy.com
I don't usually deal with anything smaller then M6.
That a head bolt for a chinese motorized bike engine?
Do you need merely mechanically similar ones or is this finish work that has to look nice?
I found these guys but they don't look like what you want.
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