Ping ISI Irons - Why ISI-C, ISI-N & ISI-K?

[Q.Q.Quillume]

I recently bought a set of Ping ISI-N irons off eBay and find that Ping made four "models" of the ISI irons: ISI-C (copper), ISI-N (nickel), ISI-S (stainless steel) and ISI-K (oversize stainless steel).

I'm wondering why Ping made the ISI irons in copper, nickel and stainless steel, but do not wonder why they made two models (regular and oversize) of stainless steel.

Was it strictly a cosmetic thing with each metal (copper, nickel & stainless steel) having a different look or was there also some characteristic of each metal that had some minor or major effect on playability? If there was an effect/s on playability, what effect/s?

If any Sand Trappers have any information or opinions on these questions -- THANKS!

[BD57]

stainless steel was (and still is) the standard metal Ping works with.

IMO, berrillium (sp?) copper showed up in the ISI's as a carryover from the Ping Eye 2's; BC was introduced into the Eye 2 line as giving a different, more 'forged' like feel at impact (at an upcharge).

Nickel in the ISI's was evolutionary - another metal for a different, perhaps "improved" feel. Also at an upcharge.

A lot of people worked with nickel in those days - Ping made putters in SS, BC & Nickel, Cleveland used a nickel alloy in their classic "Designed By" 8802-style head.

Eventually they all stopped. I've read that the manufacturers eventually decided the difficulty in working with the materials wasn't worth it; my guess is, after a while, consumers decided nickel & BC wasn't worth the upcharge.