Description
Narex stone chisel with hand guard is a flat-bladed striking chisel for working stone, masonry and concrete. The chisel is forged from Cr-Mo-V tool steel. Chromium, molybdenum and vanadium give the alloy the impact toughness that constant hammer blows on the head of the chisel require.
The shank is polygonal, so the chisel does not turn in the hand between blows and the position of the blade stays under control. A flexible hand guard is slipped over the shank, covering the area around the striking end and taking a missed hammer blow. The guard also reduces the vibration the chisel transmits to the hand.
The blade is flat and ground with a double bevel. The tip splits the material by wedge action: the chisel is placed at the point you want at an angle of about 60–70 degrees to the surface and advances blow by blow along the groove. The shank is painted to protect it from rust, and the blade and striking end are unpainted.
Available in four sizes: 10 x 110 mm, 10 x 150 mm, 15 x 125 mm and 15 x 200 mm. The blade width determines the width of the groove and the striking energy needed: a narrow 10 mm blade concentrates the force on a small point for precise grooving, while a 15 mm blade removes a wider strip at a time. The length of the shank determines how deep into the work the chisel reaches.
Intended use and suitability:
The stone chisel is intended for cutting, grooving and surface removal of mineral materials by hand, where mechanical chipping would break too much of the surrounding structure.
- Demolishing and repairing masonry: cutting bricks, removing joint mortar and removing a single brick while sparing the structure.
- Local working of concrete: removing small projections, casting burrs and the edges of concrete pours.
- Grooving: opening grooves for electrical and pipe installations in a masonry wall when a narrow, controlled groove is needed.
- Stone carving and natural stone: shaping split faces and roughening stone surfaces.
- Removing mortar and coatings: removing hardened mortar, tile adhesive and levelling compound from the substrate.
- Restoration: opening old joints without damaging the adjacent bricks.
Package contents:
- 1 stone chisel in the selected size (10 x 110 mm, 10 x 150 mm, 15 x 125 mm or 15 x 200 mm)
- Hand guard fitted to the shank
Features:
- Cr-Mo-V tool steel: an impact-tough alloy that withstands repeated hammer blows without breaking.
- Hand guard: takes a missed blow and dampens vibration transmitted to the hand.
- Polygonal shank: the chisel does not turn in the hand and the position of the blade stays under control.
- Flat double bevel: the wedge action splits the material along the groove.
- Four sizes: blade width 10 or 15 mm and shank length 110–200 mm.
- Painted shank: protects the surface of the shank from rust in site conditions.
- Sharpenable blade: the tip is ground back to its bevel after wear.
Technical specifications:
- Blade material: Cr-Mo-V tool steel.
- Blade type: flat, double bevel.
- Shank shape: polygonal.
- Hand guard: flexible guard slipped over the shank.
- Size 844301: 10 x 110 mm.
- Size 844302: 10 x 150 mm.
- Size 844303: 15 x 125 mm.
- Size 844304: 15 x 200 mm.
- Materials worked: brick, masonry, concrete, natural stone, mortar.
Narex stone chisel with hand guard instructions for use:
Choosing the size: Choose the blade width according to the width of the groove and the shank length according to how deep the chisel needs to reach. A narrow 10 mm blade concentrates the striking energy on a small area and advances in hard material; a 15 mm blade removes a wider strip from softer mortar and brick.
Starting: Mark the cutting or groove line. First make a continuous groove along the whole line with light blows, and only then deepen it. Going too deep at one point leads to an uncontrolled break.
Striking technique: Hold the chisel below the hand guard and place the blade at an angle of about 60–70 degrees to the surface. Strike the head of the chisel squarely with a hammer, with short, controlled blows. Use a ball-pein hammer or stone hammer: the hardened head of a claw hammer can chip when it hits the head of the chisel.
Maintenance of the striking end: Check the striking end regularly. When a spread edge, a mushroomed burr, forms on the head, grind it off with a grinding wheel. A spread burr can chip off when struck and throw a fragment.
Sharpening: Grind the bevel of the blade to its original angle with a grinder or hand stone. Cool the blade in water often: a tip that has turned blue from heat has lost its hardening and softens.
Storage: Wipe the chisel dry and store it in a dry place. Protect the tip from knocks during transport.
Warnings:
- Always wear safety glasses: sharp chips fly off stone and concrete at high speed.
- Wear protective gloves and ear defenders; for long jobs, also a respirator because of quartz dust.
- Do not strike the head of the chisel with a claw hammer or any other hardened hammer, as both surfaces can chip.
- Grind off a spread, mushroomed striking end before use; it chips and throws fragments.
- Do not use the chisel as a lever: the flat blade breaks under sideways load.
- The hand guard does not remove the risk of pinching, so take care not to trap your fingers between the chisel and the hand guard.
- Before grooving, make sure there are no electrical cables or pipes running in the wall.
- Do not let the blade heat up to blue when sharpening; it loses its hardening.
- Keep out of the reach of children.
Frequently asked questions (FAQ):
What sizes does the Narex stone chisel with hand guard come in? Four sizes: 10 x 110 mm, 10 x 150 mm, 15 x 125 mm and 15 x 200 mm. The first number is the blade width and the second the length of the chisel.
What is the hand guard for? It takes a hammer blow that misses the head of the chisel and dampens vibration transmitted to the hand.
What is Cr-Mo-V steel? A chrome molybdenum vanadium alloy tool steel whose impact toughness withstands repeated hammer blows without the blade breaking.
Which hammer is used to strike the chisel? A soft-headed ball-pein hammer or a stone hammer. When struck with a hardened claw hammer, both surfaces can chip.
When should the striking end be ground? When a spread, mushroomed edge has formed on the head. Grind the burr off before the next use.
Can the chisel be used to break up concrete? Yes, locally: for removing projections, casting burrs and edges, and for grooving. For large-scale demolition, a breaker is used.
How is the blade sharpened? By grinding the bevel to its original angle and cooling the blade in water often so that the hardening is not lost.
Recycling instructions:
Take a discarded chisel to metal collection. Remove the hand guard from the shank and sort it into plastic or mixed waste. Stone, brick and concrete waste from the work belongs in the mineral fraction of construction waste, and fine stone dust is collected separately with a vacuum. Sort the cardboard packaging into cardboard collection.
