The traditional way of securing a wooden shaft to the head is by using a wedge driven into the top of the hammer handle. This spreads the wood into tight contact with the eye of the head.
The final thing to know about hammer construction concerns the join, how is the hammer head bonded to the shaft in a secure way that can withstand great forces?
The process is different for each of the shaft types we discussed before:
This join is then sealed with oil or varnish to prevent the shaft drying out and coming loose as it shrinks.
The handle is bonded to the head using injected resin - this provides a permanent joint that's both tough and waterproof.
The tubular shaft is hydraulically pressed into the eye of the head using about 5 tons of pressure. Again the joint is permanent and tough.