I learnt to make hay rakes this year, partly because of an order for 5 children sized hay rakes from the Great Glen Community Wildspace group in Leicester.
I made the handles from ash and sallow, all in slightly different designs because there is more sallow than usable ash in the new wood. Some have forked branches which I thought would be naturally strong, they seemed to work fine.
I used dried silver birch for the tines or teeth - bashing the roughed out dowels through a tine cutter of 11mm to make clean dowels. The tines are set in at approx 1.5" to 2" spacing across the green ash head and flats are put on the backs so the tines don't split.
The handles are drilled into the head at a 70 degree angle to make a good rake, making sure you get this the right way up! Wedges hold the handle onto the head so it was solid. After doing a set of rakes the process became easier, but like most things not tried before there was some head scratching at first.
All full test of the adult sized hay rakes proved they worked great. Martin spent many hours in the mornings mowing the rides with his scythe and the hay rakes did their job well.