Thanks evreyone, I shall have a go today; Invaluable advice.
I must say I had not come across rolled pins before but have now ‘googled’ them and understand what they are for. I found this short piece which may interest others:
The spiral spring concept represents broad design
latitude in the control and development of pin
fl exibility. The engineered fl exibility of Spirol® coiled
pins provides for compression of the pin into the hole
and for continued fl exibility after insertion. Without
this fl exibility, the total load applied to the pin would
be transmitted to the hole wall without dampening
the impact. Since the hole material is normally softer
than the pin, elongation or enlargement of the hole
would result. The fi t between the hole and the pin
would become loose, increasing the impact force and
accelerating the rate of hole damage. The inevitable
result would be premature failure of the assembly.
In properly engineered applications, the fl exibility of
Spirol® coiled pins dampens shock and vibration, thus
eliminating hole damage on all the components of the
assembly resulting in maximum product life.