Features; 1.Diafferent sizes available 2.Tapered drill rods; 3.Raw materials; 55SiMnMo, 95CrMo 4.Taper; 7, 12 5.Length under collar[ mm] ; 610.1220.1830.2000.2435.2740. 3050.3660 .Integral drill roads; 1.Raw materials; 55SiMnMo.95CrMo 2.Shank sizes; H22* 108MM[ 7/ 8* 4-1/ 4] [ H25* 108MM] 3.Length under collar [ mm] ; 400.800.1200.1600.2000.2400.3200.4000.4800 4.Bit diameter [ mm] ; 29.30.31.32.33.34.35.36.37.38.39.40.41. Shandong Yanggu Rock Drilling Tools Factory Website: www.qianju.cn www.ygqj.en.alibaba.com Email firstclinton@ gmail.com MSN; xiaomei1011@ live.cn TEL: 0086-0635-6215089 15969607526 Fax: 00 86-0635-6366988