ASME B107.50M-1998 — Brick Chisels and Brick Sets: Safety Requirements

28 10 月, 2026
ASME Standards

🧱 ASME B107.50M-1998, an American National Standard published by the ASME B107 Committee, establishes safety requirements for the design, construction, testing, and use of brick chisels and brick sets. These tools are intended specifically for scoring and cutting brick and masonry block and are everyday tools in masonry, repair, and demolition work: the brick chisel has a narrower edge used to score a split line on the brick face, while the brick set has a wide, flat edge that splits the brick with a single blow along the scored line. The Standard’s lineage traces to the ANSI/HTI B209 series; it was issued on November 13, 1998.

💡 Brick chisels and brick sets work on brittle materials (brick, concrete block), so the edge needs wedge-and-split capability rather than razor sharpness. Edge angle, body length, and struck-face design are therefore optimized around “a clean split along the scored line with one blow.”

1. Scope and General Framework 📌

Section 1 (General) states that the Standard provides safety requirements for the design, construction, testing, and use of brick chisels and brick sets, whose intended use is scoring and cutting brick and masonry block. Key points:

Only safety-relevant design, test, and use details are specified; manufacturing processes are not;
It serves as a guide in selecting, testing, and using the tools covered;
It supports the development of manuals, posters, and safe-practice training;
It may be used by state authorities or other regulatory bodies and is intended for voluntary use by establishments that use or manufacture the tools.

Referenced documents include ANSI Z87.1 (occupational and educational eye and face protection), ANSI Z535.4 (product safety signs and labels), the ASTM bar and tool-steel specifications (A29/A29M, A322, A331, A576, A681), ASTM E18 (Rockwell hardness), and the HTI Guide to Hand Tools.

⚠️ Brick chisels and brick sets are limited to scoring and cutting work. Chiseling concrete foundations, prying metal, or striking hard aggregate is out-of-scope use: the edge will shatter, the body will bend, and the risk of flying fragments rises sharply.

2. Construction and Design Requirements 🔧

Section 4 (General Requirements) is organized into design, materials, mechanical properties, and tests (nomenclature and bevel configurations in Figs. 1 and 2). The principal parts of a brick chisel or brick set include:

Part	Name	Requirement / Function
Struck face	Struck Face	The end that receives hammer blows; may be flat or a rounded head design
Body	Body	The straight portion connecting struck face and edge; must transmit impact with adequate strength
Taper	Taper	The transition narrowing toward the edge, balancing strength and wedging action
Bevel	Bevel	The slope adjacent to the cutting edge; its configuration is specified per Fig. 2
Cutting edge	Cutting Edge	Wide on the brick set, narrow on the brick chisel; used for scoring and splitting

🚨 The bevel configuration of the brick set directly governs splitting effect and safety: too steep an edge digs in too deep, causing edge chips and flying fragments; too flat an edge will not split the brick. Fig. 2 prescribes the configurations for both tools — regrind only to the original geometry.

3. Materials, Mechanical Properties, and Tests 🧪

Section 4 also covers materials, mechanical properties, and tests:

Materials: carbon and alloy steel bars, special-quality hot-wrought/cold-finished bars, alloy tool steels (ASTM A29/A29M, A322, A331, A576, A681);
Mechanical properties: after heat treatment, the edge and body must reach the specified Rockwell hardness range at the prescribed locations (per ASTM E18), while the edge stays resistant to spalling;
Tests: specified static or impact loads are applied per the Standard’s methods to verify the load capacity of the edge and body;
Acceptance: after testing, no cracks, chips, or permanent distortion affecting safe use may appear.

Because these tools split brittle materials by impact, edge duty is harsher than for metal chisels, and the Standard’s hardness control plus impact testing is the key barrier against “shattering edge fragments.”

4. Safety Requirements and Limitations of Use 🛠️

Eye protection: brick dust and fragments fly at the instant of impact; operators and bystanders must wear eye and face protection per ANSI Z87.1;
Correct gripping: hold the mid-to-rear of the body with the hand clear of the edge direction; hold the hammer perpendicular to the struck face;
Struck-face upkeep: grind back or discard any mushroomed struck face immediately;
Score-then-split sequence: score a sufficiently deep line with the brick chisel first, then split with one blow of the brick set along the score — never strike unscored areas directly;
Workpiece support: place the brick on a stable surface or dedicated support; never hold it in the hand while striking;
Marking and training: safety signs per ANSI Z535.4 and training per this Standard.

5. Engineering Practice Essentials ⚙️

Sequenced work: the brick chisel (scoring) + brick set (splitting) combination is the standard procedure; deep scoring before splitting markedly reduces fragments and mis-splits;
Resharpening: regrind to the original bevel configuration of Fig. 2, cool thoroughly to prevent annealing, and re-verify hardness;
PPE programs: masonry procedures should include goggles, screens, anti-slip gloves, and training;
Procurement acceptance: request hardness and test data from suppliers as the basis for incoming inspection.

6. Frequently Asked Questions ❓

❓ Q: What is the difference between a brick chisel and a brick set?
A: Edge width — the brick chisel has a narrower edge for scoring a split line on the brick face, while the brick set has a wide, flat edge that splits the brick with one blow along the score. The Standard defines separate bevel configurations for the two.

❓ Q: Why must you score before splitting?
A: Brittle material concentrates stress along the scored line, so the brick set splits cleanly with one blow; striking unscored brick directly will not split it and produces irregular flying fragments.

❓ Q: Can a chipped edge still be used?
A: No. A chipped edge makes the split direction uncontrollable, and the notch acts as a stress raiser that accelerates further chipping. Regrind to the original geometry or discard.

🔍 Q: Can this Standard be used for concrete or stone?
A: The scope is limited to brick and masonry block. Concrete and stone are harder and need dedicated tools (e.g., diamond blades); using brick chisels/sets on them ruins the edge quickly and raises fragment hazards.