Any advice on how to properly size my hammer handle? I've recently giving myself tennis elbow because of the death grip I had on the handle. It seems the current handle is to small. I'm wondering if there is a method to determine the proper handle size for my hands other than trial and error...

Thanks!

Just a little tip you can take it or leave it, but I like to put a little pine tar like what the baseball players use on their bats on my hammer handles. Just my .02.

Eat broccoli use rubber bands from broccoli to exorcise your hand opening muscles.  The cross section of your hammer is more likely the culprit.  The oval and round handles allow the head to spin on you there by requiring you to have a death grip on it.  I make my handles rectangular with 2 opposing corners removed.  Depending on wether it is right or left handed intended use.  My top tooling have just rectangular handles with corners ever so slightly rounded.  This type of handle works with the way your hand is made to stop the head from rotating allowing you to hold it with just your pointer and thumb while forging.  I can't go back to swinging other peoples handles they just hurt my hands way to much.  It also helps to remove any finish from the wood.  Also make sure your thumb is on the side of your hammer all the time and not along its back.  The vibrations will travel up your thumb and into your elbow.  you want the rebound to pivot the hammer in your hand not be absorbed by the tendons and muscles in your arms.  those 4 things should help you :D  Just my experience try them.  The size of the rectangular handle will be the rectangle of space between thumb and forefinger when your hand is relaxed.  

I agree with the rubber band idea. I've told people to do this to balance out their muscles. We spend a lot of time gripping and it makes our elbow out of balance. Exercising the fingers out balances this out.

The following is what I've found works for me. My opinion only.

As far as the profile and size of the handle I like an oval that fits my hand when closed on it.  My fingers almost touch my palm (1/8" to 1/4" away). If I squeeze tight I can just touch my palm. I modify all my handles to this size and use them all day long. When I'm hammering I use a loose grip and you should be (theoretically) able to take the hammer from my hand. Just like a tennis player I don't want to have a death grip on the handle.

Good advice above re handles and rubber bands.  Circumference of handle could also be an issue, a lot of factory hammer handles are too big around, ymmv depending on the size of your hands.  A large handle, one coated in varnish, or one that tapers the wrong way will lead to over gripping.

 

Too much too fast or binging and purging are also ergonomic issues.  Slow and steady skeletal/muscular build up is the way to go.  Do you go great guns for 3 or 4 hours every Saturday or do you do some work every day?

Handles today are a result of standardization in manufacturing, and are not indicative of the best ergonomic shape.  They're generic, and the polyurethane finish applied to them does more harm than good.  It's a sales need, not an end-user need.

 

On most commonly available hammer handles, I always choke up to the largest portion because I have large hands.  If you have long fingers, you should look into making handles that are larger so you can get a full, comfortable wrap on the handle.

I also subscribe to the rectangular handle, as I find it, alongs with a properly radiiised face keeps the hammer from jerking around in my hand. I wipe a mix of bees wax, Turpentine and linseed oil on them (the wax gives a little tac to improve grip)

The hammer eye size more or less gets you into the available handles unless you are making them from scratch. At $3.50 a piece for an ash handle, its a lot cheaper, time wise, than making one.  I find the oval eye handles for a machinist's hammer at 16 " (handle) work the best.  The round handle shapes don't work right for me. I take the store bought handle to the belt sander and create a rectangular shape with eased corners. It's all personal preference. I just like the hand orientation on the rectangular flats as opposed to the feel of a round surface. Also, I find the flats allow you better control for precise in close forging. After assembly,  I soak the newly made up head in anti freeze overnight. This virtually eliminates loose heads from any shrinkage due to drying.  I use the combo linseed oil thinner mix on the raw wood, it's easy on the hands and it prevents cracking.  

 

Peter

tennis racquet grip size

 

Is this any help?

I just measured my hand and a couple of handles I like and mine are bang on the money.

4-7/8" dia 1-1/2" height 1-3/16" wide octagonal shape

the holding of handle is a skill that has to be learned. when you grip the handle your fingers should not reach you thumb. Then you should hold it loose. If you were hammering and I walked by I should be able to grab the hammer and you would be holding it so loosely that it would stay with me. Hope this helps.

I'm another one for the oval style handle with flatish sides. I get mine so my middle finger is almost touching my palm. And another trick backwoodsblacksmith taught me was to wrap the handles in the electrical friction tape. gives just the right amount of grip so you can relax your hand more and not have to keep a death grip the whole time. At very least take some light sandpaper and get rid of that slick varnish clear coat junk that comes on most handles...

the length of the handle may be part of the problem as well.

One reason for your elbow pain is you may be allowing your elbow to move away from your side..as well as holding the hammer too tight. Another thing to think aboiut is fatigue..It takes a long time to build muscle memory and the tool skills to match. Woriking with other smiths and or observing how they work will help..hands on instrucion by a qualified smith can analyze wot you aer doing and may get youi straightened out the best way. If you watch enough u tube videos you may likely become confused as to wot is correct and wot is  harmfull to your body.  Find a local group for starters..

Are you sure it is the handle that is the problem? too heavy a head may also be an issue...one size does not fit all.

Was any of the information in the above thread,,modifying store bought hammers. of any help?

I like handles with a good terminal bulb  so I can loosen my grip and not worry about the handle slipping out of my hand.  A farrier's rasp is good for roughing in changes.

 

Another "sticky handle" trick is to rub some real beeswax on the handle.  it will be sticky at hand temp

I have heard pine tar does great things. Time to resize some handles as I can wrap my thumb all the way around to my knuckles. (I have REALLY long fingers)

Finger length can be adjusted with many power tools!

Trying not to laugh in my school library. It's a challenge...