Deep Hole Marking Pencil - STROXX, 2B, with Built-in Sharpener, 101-638

STROXX Deep Hole Marking Pencil, 2B, 101-638

STROXX 101-638 is a marking pencil for deep holes. It marks up to 100 mm deep through a 3 mm hole and up to 145 mm through a 6 mm hole. The leads are 2B and 120 mm long. A sharpener is built into the sleeve.

The problem it solves

Fixing through finished cladding means drilling a hole and then marking the structure behind it - for an anchor, a bracket, a run of services. An ordinary pencil will not reach: the point is short, the body is thick and the hand covers the hole. This marker has a thin, long point that passes through the hole and leaves a mark on the far surface with nothing taken apart.

The two depths

The figures mean different things depending on the hole. Through a 3 mm hole the point reaches 100 mm; through a wider 6 mm one, 145 mm, because a wider hole lets the thicker part of the point enter. So the depth follows the diameter rather than being fixed.

2B hardness

The lead is 2B - softer than the usual HB. A soft lead marks under light pressure, which is essential when the point is thin and long: with a hard lead the pressure needed for a visible mark simply snaps the point. 2B also writes on rough and dark surfaces where HB is barely visible.

The built-in sharpener

A sharpener sits inside the sleeve. That is no small addition: a thin point breaks often, and without a sharpener to hand the marker is useless on the spot. As it is, the tool is restored in seconds with nothing to hunt for in the bag.

Seeing the mark afterwards

The practical limit of any deep-hole marker is not the reach of the point but how visible the mark is afterwards. Through a 3 mm hole what appears is a dot a few millimetres across, not a cross. So the working method is: mark, then open the hole out or take the cladding off, and only then work to the dot. Trying to hit an anchor straight through the narrow hole on a mark nobody has seen usually costs a second hole.

What it writes on

The marker writes on timber, plastics, ceramic tile and metal - which is to say on everything actually found behind a piece of cladding.

Technical specifications

Questions and Answers