Press Fit Hammer

lellasone said:
Mikey - What you are describe - the head flying off - is my worst nightmare for this project. When you say pin the head on, do you mean drilling a pin through the side of the head through the portion of the neck inside the head?
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Yes, I would use either a roll pin or a solid pin (steel). Roll pins are hardened and are perfect for this job. If you drill a 1/8" hole through the side of the head, right through the part of the handle that fits inside the head, that roll pin will hold the head solidly. If it ever needs to come out you can drive it out with a punch. The roll pin can be ground to length so it fits the width of the head perfectly.
 
Ah, a hammer for demolition needs to be pretty solid. A small hammer like that will have to work very hard to reduce a piano to 6'' pieces so pinning is a must. Does the 'scrap metal' need to be assembled into a hammer on site? If so maybe make it a close slip fit and use a couple of set screws into pockets instead of a pin to secure the head to the handle. That way the screws can be tightened on site as needed.

BTW you might have trouble passing that off as scraps, it sure looks like a beautiful hammer to me.
 
At only half an inch, a 1.5 mil interference fit is VERY agressive, heating
the iron to 400F only expands the hole by 0.0011. I'd cut it down to .001 interference.
If retention is an issue, drill and bellmouth an exit aperture in the head, and peen
the handle to rivet it in place. If it has to be pretty, bellmouth the head
and center-bore the handle, and force a cone into the center-bore
with some loctite or a light knurl, to wedge the assembly.

0.005" of bellmouth is a lot (wood-handle hammers use twenty times that).
 
Have seen many projects like these here before and it let me thinking about metal handles vs wood handles.
I think wood handle is more confortable due some vibration dampening but yes, metal handles look awesome and is durable.
Don't you guys who made metal handles had some harsh feeling?
 
Roll pins are not hardened. They are soft. Many people incorrectly interchange the terms "roll pin" and "spring pin". A roll pin is actually a strip of metal rolled into a size slightly larger than the hole it will fit, and compresses as it is pressed or driven in. Once removed, it will not return fully to the original size. It is malleable.

On the other hand, a spring pin, aka split pin by some, is hardened and is a single turn of spring steel that is just shy of the actual calculated circumference of the target hole, giving it the gap, or split. If measured, they are a bit oversize as well, like the roll pin, but unlike the roll pin, when removed they will return close to the original size. They are considered reusable, whereas true roll pins generally are not.
 
Tony Wells said:
Roll pins are not hardened. They are soft. Many people incorrectly interchange the terms "roll pin" and "spring pin". A roll pin is actually a strip of metal rolled into a size slightly larger than the hole it will fit, and compresses as it is pressed or driven in. Once removed, it will not return fully to the original size. It is malleable.

On the other hand, a spring pin, aka split pin by some, is hardened and is a single turn of spring steel that is just shy of the actual calculated circumference of the target hole, giving it the gap, or split. If measured, they are a bit oversize as well, like the roll pin, but unlike the roll pin, when removed they will return close to the original size. They are considered reusable, whereas true roll pins generally are not.
Click to expand...

I stand corrected, Tony.
 
Thanks Tony. I was not aware of the difference between a roll and split pin. At 78 I was sure I knew everything. At the rate I'm going I'll soon be as smart as a teen ager.
 
Dulltool17 - I have been having more trouble than I would like to admit figuring out what a roll pin is via google. Do you mean these kind of things: Harbor Freight Link.


Yep!= well actually that is a spring pin, but it is what I had in mind. I think 1/6" is big enough and 1/8 might be too big.

Maybe 3/32" (.093)
 
Well, just for fun, let's add a little more confusion. There is also a "groove pin". Basically a dowel pin with a linear placed vee bottomed groove rolled or pressed into it. Usually just one. But because the method of grooving is a displacement method, the edges of the groove are upset and make the pin fit tightly in a precision hole. Usually these work best in a closely sized hole and are pressed or driven in.
A variation is a pin with upset serrations a short distance from one end only, sort of a "head" if you will. The advantage of these is they don't tighten up in the hole until you reach the serrated area near the end. So you can actually hand assemble something to check for alignment and fit before driving the pin into final positions. You will see these in assemblies where there is a piece captive yet not immobilized between two close fitting holes either side of it. Think gun parts like a trigger or hammer. They have to be free to move, but the pin obviously has to be secure against movement. It's just alternative to having the moving part with a clearance hole allowing a regular dowel pin in it. You won't see too many roll or spring pins in applications such as those.
 
wawoodman said:
Agreed. Pin it.
Click to expand...
That is what I would do to
Pein it with a ball Pein hammer make your handle long 1/8
.001 or .002 press fit then Pein that 1/8 good and tight
 
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