Good Screw Sizes fo General Use

[Jared]

Originally Posted by mman1506

What's the advantage of using socket head over button head?

Socket head typically has a deeper hex, so it's harder to strip out.

I like 10-32's over 10-24's because it's harder to break the 10-32 tap. As a rule of thumb, I try to get more than 6 threads of engagement in a tapped hole in aluminum. With a 10-32, that works out to 6/32 = 0.1875", but a 10-24 requires 6/24 = 0.250".

Once you've used both for a while, it becomes easy to identify the different threads on bolts, and you can check to see if your nut threads easily on a known bolt.

We've used 1/4-20's as axles for flywheel shooters and pivots for catapult shooters, as well as gearbox mounts.

3/8-16 or 3/8-24 is our favorite for dead axles.

[Michael Hill]

Originally Posted by Jared

Once you've used both for a while, it becomes easy to identify the different threads on bolts, and you can check to see if your nut threads easily on a known bolt.

You must not have "determined" kids that will get that 10-24 nut on the 10-32 bolt. Yeah sure, it'll go on...with enough torque.

[Oblarg]

Originally Posted by Michael Hill

You must not have "determined" kids that will get that 10-24 nut on the 10-32 bolt. Yeah sure, it'll go on...with enough torque.

Quoting for truth. As mentioned earlier in the thread, our solution to this problem is to just not buy 10-24 anymore, which removes the potential for the error in the first place. On a team as large as 449, it's just not worth the hassle for the few places where it's nice to have coarser thread.

[Mr V]

Originally Posted by Jared

Socket head typically has a deeper hex, so it's harder to strip out.

I like 10-32's over 10-24's because it's harder to break the 10-32 tap. As a rule of thumb, I try to get more than 6 threads of engagement in a tapped hole in aluminum. With a 10-32, that works out to 6/32 = 0.1875", but a 10-24 requires 6/24 = 0.250".

Once you've used both for a while, it becomes easy to identify the different threads on bolts, and you can check to see if your nut threads easily on a known bolt.

Not only does the socket head have a deeper tool engagement the tool size is usually larger for the socket head making it less likely to damage the tool or bolt. The button head is also weaker than the socket head.

Because the fine threads are not as deep (the reason it is harder to break the tap) you need more of them to have the same strength. If you look at standard nuts you'll find that their height is equal to the diameter of the bolt they work with regardless of the pitch. In other words 4.5 10-24 threads will give you the same or greater strength as 6 fine threads. The fine thread bolt will be stronger but in both cases the threads will pull out well before the bolt fails since you need 2x bolt diameter in aluminum to make the tapped threads roughly equal to the bolt strength.

It is true that once you've worked with threaded fasteners for a while it does become second nature for many people. The problem is that there are a new group of people added every year many of whom are experiencing using threaded fasteners for the first time. Because there are many new people every year that is another reason to not use fine thread fasteners because they are mush easier to cross thread.