Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
ASME B107.49-2004 — Nail Sets
🔨 ASME B107.49-2004, published by the ASME B107 Committee, establishes performance and safety requirements for nail sets — the countersinking tools used to drive unhardened finishing nails below the surface of the material being nailed. Nail sets are widely used in carpentry, interior finishing, and furniture making. The Standard supersedes the 1998 edition (B107.49M-1998) and descends from the former B209 series: after the B209 Committee merged into B107 in 1996, the B107 scope expanded to safety considerations, and this edition follows the uniform “performance requirements + tests + safety” format.
💡 The working end of a nail set is a concave cup: it caps the nail head and concentrates the hammer blow onto the nail shank, driving the finishing nail below the surface without damaging the wood. The cup diameter must match the nail-head size.
1. Scope and General Framework 📌
Section 1 (Scope) states that the Standard provides performance and safety requirements for nail sets whose primary purpose is setting unhardened finishing nails below the surface of the material being nailed. The Standard serves as a guide in selecting, testing, and using the tools, supports the development of manuals, posters, and training, and may be referenced by regulatory bodies. Manufacturing details are not specified.
Referenced documents include ANSI Z87.1 (occupational and educational eye and face protection), ANSI Z535.4 (product safety signs and labels), ASTM E18 (Rockwell hardness test methods), and the HTI Guide to Hand Tools — Selection, Safety Tips, Proper Use and Care.
⚠️ Nail sets are intended only for unhardened finishing nails. Used on hardened steel nails, screws, or bolts, the cup will chip and the head will slip, causing uncontrolled impacts and flying fragments.
2. Classification and Nomenclature 🔧
Section 2 (Classification) defines two types of nail sets (nomenclature in Figs. 1 and 2):
| Type | Name | Construction | Typical Use |
|---|---|---|---|
| Type I | One-Piece Nail Set | One-piece forging: head, body, taper, and cup; head with chamfer and lesser chamfer | General-purpose wood countersinking; the most common type |
| Type II | Self-Centering (Center Punch) Nail Set | Return spring with internal punch that self-centers on the nail head | High-volume, one-hand, or precise-centering operations |
Principal parts include the struck face (which receives hammer blows, with a chamfer and lesser chamfer to prevent edge spalling), the body (the straight portion between head and taper, used for gripping), the taper (the narrowing section toward the point), and the point end with its cup working surface, whose cup edge seats on the nail head. In the Type II design, the internal punch first contacts the nail head to center itself, then transmits the hammer blow; the return spring re-cocks the punch after each stroke.
🚨 If the return spring deforms or the punch wears so that centering fails, the hammer blow will drive the nail set off the head directly into the work surface, damaging the workpiece and endangering the gripping hand. Replace the tool immediately when centering degrades.
3. Performance Requirements and Test Methods 🧪
Sections 5 (Performance Requirements) and 6 (Tests) specify the following essentials:
- Material and hardness: nail sets shall be made of materials meeting the performance and safety requirements, heat-treated to the required Rockwell hardness at specified locations (verified per ASTM E18), ensuring cup wear resistance and body toughness;
- Cup geometry: the cup diameter and depth must correctly accommodate the corresponding nail-head size, and the cup edge must be free of chips;
- Performance tests: specified impact or static loads are applied to verify the cup, body, and struck face under countersinking duty;
- Acceptance: after testing, no cracks, spalling, or permanent distortion affecting safe use may appear, and the cup must still seat the nail head correctly.
4. Safety Requirements and Limitations of Use 🛠️
- Eye protection: nail heads or fragments can fly during striking; operators must wear eye and face protection per ANSI Z87.1;
- Correct gripping: grip at the mid-to-rear of the body with fingers clear of the point direction; hold the hammer perpendicular to the struck face;
- Size matching: choose the cup size by nail-head diameter — an oversized set damages the wood surface, an undersized one slips;
- No hardened fasteners: use only on unhardened finishing nails;
- Inspection: discard nail sets with chipped cups, mushroomed struck faces, or bent bodies;
- Marking: safety signs and size identification per ANSI Z535.4.
5. Engineering Practice Essentials ⚙️
- Kit management: keep sets covering common nail sizes (e.g., 2d–16d finishing nails) and post a size cross-reference chart at the bench;
- Hand technique: touch the cup to the nail head vertically to confirm centering, sink the nail with short hammer strokes, and finish with a wooden block to avoid striking the surface;
- Maintenance: regrind a dulled or deformed cup to the original geometry, recheck hardness, and keep the steel cool;
- Procurement acceptance: request hardness and performance test data from suppliers as the basis for incoming inspection.
6. Frequently Asked Questions ❓
❓ Q: How do I choose between Type I and Type II nail sets?
A: Type I is simple, general-purpose, and low-cost — ideal for routine carpentry; Type II self-centers automatically via its spring-loaded punch, suited to high-volume, one-hand, or precision work.
A: Type I is simple, general-purpose, and low-cost — ideal for routine carpentry; Type II self-centers automatically via its spring-loaded punch, suited to high-volume, one-hand, or precision work.
❓ Q: Why does the Standard emphasize “unhardened” finishing nails?
A: Hardened nail heads are hard and slick, so the cup cannot seat them and they slip and chip under impact. Limiting the scope to unhardened finishing nails keeps the operation safe.
A: Hardened nail heads are hard and slick, so the cup cannot seat them and they slip and chip under impact. Limiting the scope to unhardened finishing nails keeps the operation safe.
❓ Q: What if the cup keeps slipping?
A: First check that the cup size matches the nail-head diameter; then inspect the cup for wear or chips; switch to the correct size or discard the damaged tool.
A: First check that the cup size matches the nail-head diameter; then inspect the cup for wear or chips; switch to the correct size or discard the damaged tool.
🔍 Q: How does B107.49 relate to other B107 struck-tool standards?
A: Nail sets belong to the struck-tool family, sharing the Subcommittee 4 safety framework with metal chisels (B107.47M/48) and brick chisels (B107.50M) — the struck-face/chamfer/hardness requirements follow the same technical route.
A: Nail sets belong to the struck-tool family, sharing the Subcommittee 4 safety framework with metal chisels (B107.47M/48) and brick chisels (B107.50M) — the struck-face/chamfer/hardness requirements follow the same technical route.
