Not sure if you have tried any NSAIDs or even analgesics, they may help alleviate some of your pain. If you have osteo-arthritis, you may want to try glocusamine and chondroitin. You can find these at most health food stores or pharmacies as they are supplements and you don't need a prescription from your doctor. Although I would consult with him/her before taking them.

Alternatively, I would recommend some exercises for your hand and forearm. Since you are a machinist, you probably perform a few of the same activities throughout the day. If you don't balance this out with other activities / exercises, you could run into bone/joint problems. It sounds like you may be on the cusp of this.

For strengthening your forearm, grab a weight (or anything) in your hand and do some basic wrist curls and extensions. This will work the top and bottom of your forearm. You could also work the sides by holding your arm straight down and flexing your wrist so that your fist goes toward your leg and then flexing it so it goes away from your leg. These exercises will work the entire forearm.

For your hand, grab a tennis ball or something similar in size. Hold it and squeeze. Squeeze for a count of 10-15 sec, release and repeat.

When you get done, stretch your fingers and forearm. Try this for a couple of weeks and see if your pain gets better. If not, talk to your doctor about some OTC supplements.

Hope this helps.
Brian