Help me understand tap sizes
#1
Full Member
Thread Starter
Help me understand tap sizes
i bought some taps to rethread french cranks to accept 9/16 pedals. i've bought a couple tap wrenches but they are too small. local hardware store doesn't have anything bigger.
end of taps measure between 1/4 and 1/2" and that's the size wrench i bought, but it's way too small.


end of taps measure between 1/4 and 1/2" and that's the size wrench i bought, but it's way too small.



#2
Really Old Senior Member
If you unscrew the handle, does the wedge block (for lack of a better term) move enough to insert the tap?
Maybe you'll need to pry it to initially break loose any "hindrance"?
Maybe you'll need to pry it to initially break loose any "hindrance"?
#3
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Thread Starter
i did unscrew it all the way and that's what you see in the photo. not even close. i also got the other style of tap wrench in the same size (shaped like a T) and it was also too small.
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12 or 8 point socket is what I use when I can't fit a handle in a confined location
a guide helps.
https://www.amazon.com/GATOR-TOOLS-V.../dp/B000ZN30U4
a guide helps.
https://www.amazon.com/GATOR-TOOLS-V.../dp/B000ZN30U4
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#5
Full Member
I think that when the package states, 'For tap sizes #0-1/2"', it is referring to the size of the holes that the taps would be used for - and not to the square shank sizes. So, as small as a tap for a #0 hole, and as large as a tap for a 1/2" hole.
As one point of reference, you might look at some of the tap wrenches at McMaster-Carr. They show not only the range of tap sizes, but also the range of square shank sizes.
As one point of reference, you might look at some of the tap wrenches at McMaster-Carr. They show not only the range of tap sizes, but also the range of square shank sizes.
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...the handles are usually listed by the size of the tap they will accommodate. So you need to buy something that says it will handle a 9/16" tap (a size larger than 1/2". Look here for a large assortment of them on Amazon. You need something that states it will handle a 3/4" tap, which is usually the next size up, and a little more expensive. Unless you plan on using even larger taps some day. The bigger ones will usually adjust down to handle smaller stuff.
...the handles are usually listed by the size of the tap they will accommodate. So you need to buy something that says it will handle a 9/16" tap (a size larger than 1/2". Look here for a large assortment of them on Amazon. You need something that states it will handle a 3/4" tap, which is usually the next size up, and a little more expensive. Unless you plan on using even larger taps some day. The bigger ones will usually adjust down to handle smaller stuff.
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#9
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ah ok i had a feeling i was looking at the wrong measurement. well i should be set for taps when this is all done
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i bought some taps to rethread french cranks to accept 9/16 pedals. i've bought a couple tap wrenches but they are too small. local hardware store doesn't have anything bigger.
end of taps measure between 1/4 and 1/2" and that's the size wrench i bought, but it's way too small.
end of taps measure between 1/4 and 1/2" and that's the size wrench i bought, but it's way too small.
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I have a reamer that just barely fit the largest tap handle I had with a little grinding off of opposing corners of the reamer's "square". Now I have a bigger tap handle thanks to the local tool recycling non profit shop (where I have bought a belt sander and a 4x6 powered hack saw for really good prices) Andy
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I always used to use an adjustable wrench. You could get a Knipex pliers wrench if you want to be cool about it.
There is actually a little known "short" size. Supposedly they still have it. They used to keep the cups under the counter because they were embarrassed someone would want such a small quantity of coffee
There is actually a little known "short" size. Supposedly they still have it. They used to keep the cups under the counter because they were embarrassed someone would want such a small quantity of coffee
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Sorry if this is z duplicate.
But tap handles are sized by.the thread diameter of the tap. So, you'll need to shop for one for a 9/16" tap.
In many cases, but not all, you might get by with a 1/2" handle if you grind two points off slightly to clear the frame. I've done this in a pinch, but would only consider it to save serious dough on a handle that would be the largest I expected to own.
But tap handles are sized by.the thread diameter of the tap. So, you'll need to shop for one for a 9/16" tap.
In many cases, but not all, you might get by with a 1/2" handle if you grind two points off slightly to clear the frame. I've done this in a pinch, but would only consider it to save serious dough on a handle that would be the largest I expected to own.
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An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#15
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Thanks for the advice. I didn't know how to measure a tap wrench, never done this before. But I decided to give it a try with a small wrench which worked fine. As you can tell from the photo, I'm tragically unorganized. If I bought another tap wrench I'd never be able to find it again anyway!
