Question

Explain how, the iron blade of a spade is fixed to a wooden handle

Answer 1

The hole in an blade must be made to be smaller than the wood.

This is accomplished in three different ways.

The old blacksmith's way is to heat the blade so that the hole is large enough to go over the wood and when it is cooled it will shrink down to the size of the wood. Wagon wheels are made this way.

Secondly, the wood is put into the hole of the blade and then spread out with wedges that expand the wood. Hammers are often made this way.

Thirdly, in a pick axe the blade is dropped onto the the handle from the hand end and the working end is over-sized so that it will not slip off.

Answer 2

Iron blade is heated so that it expands and fixes on the wooden handle. Then it is cooled so, that it contracts and firmly attaches to the handle.