Hex. Head screw complete ( consisting of 4 items ) for mounting of DRDE Bio- digester system. 1 ) Hex. Head Screw M16X60 ( Property class 10. 9 to IS 1367 Pt. 3- 2002 ) to IS1364 Pt- 2- 2002 2 ) Hex. Nut M16 ( Property class 10 to IS: 1367 Pt. 6- 1994 ) to IS: 1364 Pt. 3- 2002 3 ) Spring washer B16- IS: 3063- 1994 4 ) Hex. Thin Nut M16 ( Property class 10 to IS: 1367 Pt. 6- 1994 ) to Specn. IS: 1364 Pt. 4- 2003. Note: Items shall be of make