US PRO 3998 16pc 1/2" Drive Impact Hex Bit Socket Set (H4–H19)

The US PRO 3998 16 Piece 1/2" Drive Impact Hex Bit Socket Set is engineered for demanding fastening tasks where standard hand bits simply aren’t enough. Designed specifically for impact tool use, this set delivers the strength, durability, and size range required for automotive, industrial, and heavy maintenance work.

Each hex bit socket is manufactured from chromium molybdenum (Cr-Mo) steel, a material chosen for its excellent resistance to shock and torque. The bits are heat treated to enhance durability and reduce the risk of snapping or premature wear under repeated impact loading. A protective black phosphate finish provides added corrosion resistance while maintaining a professional workshop appearance.

With a 78mm overall length, these sockets offer improved reach and access to recessed fasteners, making them ideal for suspension components, engine work, machinery servicing, and structural fixings. The wide H4–H19 size range ensures compatibility with both smaller precision fasteners and larger high-torque hex applications.

Key Features & Benefits

• 16-piece impact hex bit socket set

• 1/2" square drive for impact wrenches and ratchets

• Hex (Allen) bit profile

• Chromium molybdenum (Cr-Mo) steel construction

• Heat treated for enhanced strength and longevity

• 78mm length for improved reach

• Black phosphate finish for corrosion protection

• Designed specifically for impact use

Sizes Included

H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17, H18, H19

Specifications

• Brand: US PRO

• SKU: 3998

• Set Size: 16 pieces

• Drive Size: 1/2"

• Bit Type: Hex (Allen)

• Material: Chromium Molybdenum steel (Cr-Mo)

• Heat Treatment: Yes

• Finish: Black phosphate

• Bit Length: 78mm

• Application: Automotive, industrial, workshop, heavy-duty fastening