Klein Tools LS12 L-Style Long Hex Key Set, SAE, 12-Piece

Twelve SAE (inch) sizes: 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32, 1/4, 5/16 and 3/8 inch. All inch sizes, no metric keys, so if the fasteners on your equipment are metric this is the wrong set.

No. The LS12 keys are not insulated and will not protect against electrical shock. For energized work you need keys rated and marked as insulated hand tools. Klein also warns against slipping a pipe over the key for extra leverage, and to wear approved eye protection.

Yes, these are long-arm L-style keys. The key lengths run from 3 inches up to 7 inches depending on size, so the larger keys give you real reach into recessed socket screws, set screws in pulleys and sheaves, and fasteners down inside panel enclosures. The ends are flat (chamfered), not ball ends, so you work square to the fastener rather than at an angle.

The LS12 keys are flat, chamfered ends. Chamfered flat ends seat fully in the socket and take more torque without rounding the fastener, which is what you want on tight set screws. What they will not do is drive a screw you can only reach off-axis. If your access is obstructed and you need to turn the key at an angle to the bolt, choose a ball-end hex key set instead and keep the flat-end set for breaking fasteners loose.

It will. The LS12 ships in a Twist-to-Lock caddy with interlocking cases that stack with other Klein Twist-to-Lock cases, so a tech carrying both the SAE and metric sets can clip them together instead of loose in the bag. The internal locking mechanism holds the keys so they do not shake out in transit, and you twist to release one key at a time.

Every key in the LS12 set carries a rust resistant black phosphate coating, which is what holds up to the damp and condensation a tool sees living in a van or an unheated shop. The keys themselves are CR-V (chrome vanadium) steel, heat treated and tempered, so they resist twisting under load rather than deforming on the first tight fastener.

For inch-fastener work the 1/16 to 3/8 inch spread covers most of what an MRO or building maintenance tech touches: set screws on fan sheaves and couplings at the small end, equipment mounting and guard bolts at the 1/4 to 3/8 end. What it does not cover is metric fasteners, which show up on a lot of imported HVAC and motor equipment, so crews working mixed equipment usually carry an SAE set and a metric set and stack the two cases together.

The whole caddy measures 7 inches overall length, 3.1 inches wide and 1.12 inches high, and weighs 0.8 lbs. That is flat enough to drop into a pouch pocket or a van drawer without eating a full slot. The case is orange, which makes it easier to spot on a jobsite floor.

Order Klein Tools LS12. That is the manufacturer part number for the SAE 12-piece L-style long-arm hex key set in the Twist-to-Lock caddy. Country of origin is Vietnam.