Chrome Vanadium Steel 50BV30 CHROME VANADIUM STEELLLNDEI Socket set made of drip-forged and heat-treated chrome vanadium steel (50BV30)to withstand extreme levels of torque changes against fasteners and finished with corrosion-resistant black phosphate, which is able to resist abrasion, oxidation, and corrosion, greatly extended its service life! 6-POINT DESIGNLLNDEI sockets grip flat sides of fasteners, not corners. The 6-Point hex socket design prevents round-off on nuts and bolts under high torque exertion and hammering stress from the use of impact and electric wrenches with a strong output. EASY TO CARRYThe drive socket sets include a heavy duty blow molded storage case (L11.2x W7.8x D2.4) with size labels for organized storage and is secured by two lever locks, drivers are stayed in place firmly, which is easy to carry, transport and store safely. SAE/METRI SOCKET SETThe complete set comes with the following pieces: 48 x 1/4" drive sockets -D