Bosch PRO Impact T20 Screwdriver Bit, 90 mm, 2608522535

Bosch PRO Impact T20 Screwdriver Bit, 90 mm, 1 Piece, 2608522535

Bosch 2608522535 is an impact bit in T20, 90 mm long, 1 piece per pack,, from the PRO Impact range. The shank is an impact-rated 1/4" hex.

The T20 recess

T20 is a six-lobe Torx recess. Its advantage over a cross head is geometric: force is transmitted perpendicular to the walls of the recess rather than at an angle. So a Torx bit does not cam out, needs no constant end pressure and practically never chews the head. That is what made it the standard on structural screws, furniture fittings and decking.

Up to 50 times more robust

Bosch states up to 50 times the durability of its standard 2607001528 Extra Hard bit. It comes from:

• Heat-treated modified steel - resistant to high torque instead of twisting permanently.
• An extended torsion zone - a narrowed section of the shank that absorbs the impact pulse before it reaches the tip.

An impact driver delivers torque in blows, not smoothly. Without a torsion zone every blow goes straight into the tip; with one, the shank takes the energy by twisting elastically. That is why ordinary bits break in an impact driver within hours while impact-rated ones last months.

The 90 mm length

90 mm is the long bit. It is used where the screw sits recessed, in a deep counterbore or behind an edge - furniture fittings, fixings in a deep hole, or where the driver nose must not touch the visible surface. A long bit is also less stable: it needs the machine held square to the screw axis.

Magnetic tip and colour coding

The tip is magnetic, with a black phosphate coating - the screw stays on the bit while you place it one-handed. The bits are colour coded, so you find the size in the box without reading labels.

Where T20 turns up

T20 is the middle Torx size and appears most often on lighter structural screws, furniture fittings, hinges and electrical boxes. The 90 mm length has a concrete reason there: many of those fixings sit in deep recesses or behind an edge - a hinge in a deep mortice, a screw at the bottom of a box, a fixing through a spacer.

Technical specifications

Questions and Answers