K&M 166 Piano Tuning Hammer

I tune mainly older piano's and have not yet seen one where it fits exactly. The head is too wide causing too much play or even skipping over the edges of the tuning pin, thereby damaging both tuning pins and the head. I also got the tool stuck on the pin a few times, having to forcibly remove it using other tools and risking damaging the soundboard and the pins.

Although you would not expect it, 6,5mm and 6,2mm is a HUGE difference with tools like these.

Eventually I bought the more expensive K&M 167 which comes with 3 heads and is of better quality. Like always, don't skimp on price, as this is the most important tool in tuning. I wish i'd gotten the 167 right away instead of losing money on the 166.