Allied-Locke's XDO series chains are optimized for the severe requirements of the oilfield industry. Features of Allied-Locke's XDO chain include shot peening to increase fatigue strength and improve resistance to fatigue cracking, wider waist link plates for greater resistance to shock, ball drifting of the sideplate holes to increase the life of the chain, and specialized hot dip lubrication to maximize lubrication penetration in the chain joints.