The Dirt Tricks KTM Front Sprocket is built from an ultra-hard tool steel. Most front sprockets sold today are “case hardened”, meaning that only a thin outer layer of steel is hardened. Below that layer is soft steel. Our front sprockets are heat treated, giving them the ultimate toughness and wear resistance. How can we have such a hard material without it being brittle? Shock resistant tool steel is the answer. This is the same steel used to punch holes through 1? thick plates of steel, on high speed punch presses KTM: '91-'16 All 2-stroke models 125cc and up '99-'15 All 4-stroke models 250cc to 530cc Husaberg: '09-'14 350/450/570 Husqvarna: '14-'16 TC/TE/FC/FE 125/250/300/350/450/501 Beta: '05-'16 RR/RS 2-stroke and 4-stroke models KTM ATV: '08-'10 SX/XC 450/505/525