▁" indust ry ▁standard " ▁in ▁building ▁g rip ▁strength , ▁have ▁become ▁somewhat ▁of ▁a ▁cult ▁phenomen on ▁and ▁have ▁am ass ed ▁a ▁world wide ▁following ▁– ▁one ▁British ▁strength ▁enthus iast ▁has ▁written ▁into ▁his ▁will ▁that ▁he ▁would ▁like ▁to ▁be ▁buried ▁with ▁his ▁Capt ains ▁of ▁Cr ush ▁hand ▁g ri pper . ▁ ▁In ▁ 1 9 9 1 , ▁Iron M ind ▁began ▁cert ifying ▁people ▁able ▁to ▁close ▁the ▁company ' s ▁benchmark ▁Capt ains ▁of ▁Cr ush ▁No . ▁ 3 ▁g ri pper ; ▁cert ification ▁on ▁the ▁Capt ains ▁of ▁Cr ush ▁No . ▁ 4 ▁was ▁added ▁in ▁ 1 9 9 8 ▁and ▁cert ification ▁on ▁the ▁Capt ains ▁of ▁Cr ush ▁No . ▁ 3 . 5 ▁was ▁added ▁in ▁ 2 0 0 8 . ▁ ▁Only ▁five ▁people ▁( J oe ▁Kin ney , ▁Nathan ▁Hol le , ▁David ▁Mort on , ▁Tommy ▁H es le p ▁and ▁Magn us ▁Samuel sson ) ▁have ▁been ▁cert ified ▁for ▁closing ▁the ▁No . ▁ 4 . ▁ ▁Publications ▁Iron M ind ▁has ▁published ▁ 1 8 ▁books ▁by ▁established ▁authors ▁such ▁as ▁John ▁Mc Call um , ▁Ben ▁We ider ▁and ▁David ▁Web ster . ▁It ▁has ▁also ▁developed ▁and ▁published ▁books ▁by ▁such ▁first - time ▁authors ▁as ▁John ▁Brook field , ▁Steve ▁Je ck , ▁Steve ▁Just a , ▁Brad ▁Johnson ▁and ▁Brian ▁Jones , ▁many ▁of ▁whom ▁have ▁become ▁authorities ▁in ▁their ▁fields . ▁