Monkey Tool

[Blacksmith Jim]

Whats the best way of acquiring a Monkey Tool? I'm planing on taking some 1" square cold roll I have (just mild steel I think) and drilling down it to make one. Just wondering if there is anything I am overlooking. What are you guys using? or making?

I know there is a blueprint that talks about it, but it is in the 300 set.

[Zsartell]

Mild steel should work fine for a monkey tool. I sometimes give the end of the tool a slight radius so the center sticks out a bit more. This way you are surely moving less material at one time as the center near the tenon is usually the only part sticking out. But more importantly to get a nice fit, the center near the tenon should actually go in a little further than the outer edge.

[Blacksmith Jim]

I was thinking about a slight radius on the end too the other day. Glad to hear some confirmation on that! Thanks.

[John Martin]

I just use a pipe that has a piece welded onto the back of it. Haven't actually made my own yet.

[jimbob]

chanfer the hole, also drill a hole perpendicular to the main hole so the trash will fall out

[Blacksmith Jim]

By trash, do you mean scale?

[Blacksmith Jim]

M-bro, I thought about just welding a 1/4" piece of plate on the end of a piece of pipe, I felt like it wouldn't work as well without more mass. Also I wasn't sure if the pipe would deform poorly instead of the nice mushroom I get on the end of a normal tool. How has it held up for you? Have you used a solid monkey too to compare it to? Seems easier to hit a normal mushroomed end instead of getting one side of a pipe and not the other too..

[jimbob]

By trash, do you mean scale?

yes and anything else small pieces of coal...mud dobber nest (I left mine on the bench outside...that i'll teach me to put it back in the tool box)

[petere76]

Regionalchaos,

Making monkey tools or shouldering sets, is easier than finding them. the added benefit is you get the sizes you want.

I have made sets out of (mild) round stock and square stock. The round stock was easy, I used the lathe 3 jaw to chuck the stock and drilled the appropiate size bore. I then chamfered the bore with a countersink and drilled the cleanout in the drill press. Note that the clean out is drilled at 90 deg to the bore axis at its bottom point and it is slightly larger in dia. make certain that the depth of the bore will accomodate whatever tennon you are forging. To do the same thing with square stock set up using a 4 jaw chuck and scribe the center point. Both sets work well.

Have at it and good luck.

Peter

[metalmangeler]

As you mentioned the monkey tool will tend to mushroom on the struck end. You can head this off by rounding the struck end when you make the tool and then dressing it as you use it, you don't add any value to your work with the addition of blood.
I make mine from mild steel drill for round ones drill and drift then reheat to remove drift/mandrel for square or rectangular ones.

[Blacksmith Jim]

I plan to go with square stock because I don't have access to a lathe. I figured square would be a lot easier to clamp onto a press table...

Jimbob, thanks, I hadn't thought about crap getting in the hole while its in the tool box, dropped in the shop, coal bin, etc.. That makes a lot more sense now. I'll be sure to drill the extra hole and chamfer.

mm, I try to always keep the struck end of my tools dressed. Thanks for the reminder though.

[jimbob]

the important thing is you don't have a sharp edge where the tenon meets the main body...the reason for the chanfer

[Sam Falzone]

Okay ... this is a new one for me so I'll ask ...
What is a monkey tool?
Can anyone post some pictures or a drawing?

sam

[Glenn]

A monkey tool is places on the leg of the tenon and hammered to set the shoulder. The upper hole is to clean out debris.

[ironrosefarms]

I have got some steel that I plan to make a couple different sizes. So this is very timely. What is the typical dimensions for the monkey tools you own or make? How much shoulder do you usually want around the tenon hole for an average monkey tool? (I understand that this might change for special work situations)

[Mark Aspery]

The size of your monkey tool can depend upon the size of your tenon and how you go about making it.

If you are using Top and bottom tooling to make your tenon (or a similar thing under the power hammer) then the tenon may come out a certain size. Your monkey tool should be about the same size as the HOT (expanded) tenon or slightly larger. If you wait for the tenon to cool then you will have to add a little to your drill hole measurements to compensate.

For me, I keep monkey tools around by the 1/16 for small sizes of tenons and by the 1/8 for larger ones.
1/4, 5/16, 3/8, 7/16, 1/2, 5/8, 3/4, and so on.

I like to slot punch and drift to form the eye as this aids in my skill development that can be used later to make hammers.

I like to make my monkey tools out of square stock as it will stay put on the face of the anvil and not require an appropriately sized half round bottom swage to capture it.

I like the face of the monkey tool (generally) to be convex. This will produce a slightly concave tenon shoulder. This allows for the edge of the shoulder to grip before the root of the tenon is seated.

As previously stated, make sure that the drill hole has a slight chamfer to it in order to produce a slight shoulder at the root of the tenon. This will prevent the tenon from cracking during cooling after riveting.

[Mike BR]

I read somewhere that the upper hole is primarily so you can make sure the tennon isn't bottoming out and mushrooming inside the monkey tool. Can't vouch for the truth of that myself, but it does seem like a pretty good thing to prevent. :)

[Blacksmith Jim]

Mike, thats what one of my good friends was saying to. He recommended putting a whole slot in, but I wasn't really set up to do that.

I did make a basic monkey tool last night. I made two actually, and left one for my friends shop. I used a square piece of mild steel, maybe 3/4 - 7/8th inch thick. Then went with a 1/4" hole. I chamfered it, though I haven't ground it so it is slightly rounded yet. Funny thing though, when I went to use it I found that my ability to swage down to the rough tenon shape still wasn't that good with the tools I had on hand. So next week it will probably be time to build a swage specifically to make those tenons quickly. Anyway, thanks for all the advice.

[Doug C]

I read somewhere that the upper hole is primarily so you can make sure the tennon isn't bottoming out and mushrooming inside the monkey tool. Can't vouch for the truth of that myself, but it does seem like a pretty good thing to prevent.

I have always heard that the upper hole lets the hot gasses and small scale escape gracefully. You can always feel when you have bottomed out.

Another thought on the usage of a monkey tool. I was taught to give it a 90 degree twist after each strike to prevent it from getting stuck on the tenon. The one time I didn't the tool got stuck.

[Blacksmith Jim]

Oh, thanks for that tip Doug. I was getting it stuck last night, and I just left it in place and whacked it good...

[ThomasPowers]

I've always used deep walled sockets from the fleamarket---the cheap ones that don't have a relieved edge around the driver hole.

[kube60]

Hello everyone. Been lurking for awhile but this is my first post. I was surfing around on harbor freight the other day and found these. - Harbor Freight Tools - Quality Tools at the Lowest Prices I'm wondering if in a pinch they would work as monkey tools. I know everyone says their tools are crap but I guess Ive just always been lucky with the ones I've gotten.

[Dave Hammer]

Probably not. A little more mass (actually a lot) is needed. Those tools are great for making gasket holes though. Very useful in a workshop.

[Mark Aspery]

If you are going to use a socket set or other manufactured tool to act as a monkey tool, please make sure they are devoid of any chrome plating.
The chrome comes off quite easily and is very sharp. If it comes off while hammering, it has a lot of energy and can travel some distance.

Non chromed impact wrenches can be use for square tenon shoulders.

I think it is better to make monkey tools yourself yourself -- as a blacksmith!


So how did the monkey tool get its name?

[Jeff Bly]

I was just asking someone that same question today, but he did not know the answer.

From the saying "there's a monkey on your back"?

or, "quit monkeying around"?