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ASME B107.59-2002 — Slugging and Striking Wrenches: Safety Requirements
🔧 ASME B107.59-2002 (Slugging and Striking Wrenches), issued by the ASME B107 Standards Committee on Hand Tools and Accessories, provides performance and safety requirements for slugging and striking wrenches, tools intended for torquing fasteners. Torque is applied by striking the wrench with a hammer, converting impact energy into tightening torque where a conventional wrench cannot develop enough leverage or space is restricted. The Standard’s lineage traces to B209.11 (absorbed into the B107 system after 1996) and it was approved as an American National Standard on May 13, 2002.
💡 Both slugging and striking wrenches are hammer-driven: the slugging wrench is a solid forged single- or double-head open-end wrench whose handle end serves as the struck face, while the striking wrench is commonly of box construction that transmits the blow through a struck block. The two types differ in struck-face design, hardness, and impact-test emphasis.
1. Scope 📌
Section 1 (Scope) states that the Standard provides performance and safety requirements for slugging and striking wrenches intended for the torquing of fasteners. As with other B107 documents, it serves as a guide for selecting, testing, and using the covered tools; specifies only performance- and safety-related details; does not specify manufacturing details; supports safety manuals, posters, and personnel training; and may be used by state authorities in formulating regulations.
The document is organized as follows:
- Section 1 — Scope;
- Section 2 — Normative References, including ANSI Z87.1, ASME B107.6, ASME B107.9M, ASME B107.17M (wrench opening gages), ASTM E 18, and the Hand Tools Institute guide;
- Section 3 — Definitions (box end, chamfer, equivalent, safety message, shall/should, and others);
- Section 4 — Requirements (design, materials, mechanical properties, markings, wrench openings);
- Section 5 — Tests (hardness determination and impact test);
- Section 6 — Safety Requirements and Limitations of Use.
2. Design Requirements and Reference Standards 🔧
Section 4 (Requirements) specifies:
- Design: the struck face is located at the handle end, with chamfer and shape meeting safety requirements (Figs. 1 and 2 give nomenclature for striking and slugging wrenches); the struck block cross section and struck-face interface are defined (Fig. 3);
- Materials: the wrench body is a forged steel component meeting strength and toughness requirements;
- Mechanical properties: hardness of the opening end and struck face within limits, balancing wear resistance and impact toughness;
- Wrench openings: opening sizes controlled per ASME B107.17M (reference gages for wrench openings), consistent with the sizing system of the open-end and box wrenches in the series;
- Markings: required safety messages and size markings applied to the wrench.
| Item | Requirement | Reference |
|---|---|---|
| Struck-face design | Struck face at handle end with chamfer against edge chipping | 4.1 / Figs. 1, 2 |
| Material | Forged steel meeting performance, free of harmful defects | 4.2 |
| Hardness | Opening end and struck face within limits (per ASTM E 18) | 4.3 / 5.1 |
| Opening sizes | Controlled per ASME B107.17M reference gages | 4.5 |
| Marking | Size and safety information marked per the Standard | 4.4 |
3. Test Methods 📊
Section 5 (Tests) specifies two essential tests:
- Hardness Determination Test: key areas measured per ASTM E 18, verifying heat-treatment quality;
- Impact Test (Fig. 4): a falling or pendulum weight delivers a specified impact energy to the struck face, proving the wrench does not fracture, spall, or deform excessively under hammer-driven service. The test specifications are tabulated in Table 2 (Impact Test Specifications) by wrench size, with the impact energy and acceptance criteria.
⚠️ Impact resistance — not static load capacity — is the defining performance of a striking wrench. When accepting product, review the manufacturer’s impact-test report and confirm the impact energy and setup match Table 2; do not rely on hardness values alone.
4. Safety Requirements and Limitations of Use 🛠️
Section 6 (Safety Requirements and Limitations of Use) includes:
- Strike the struck face only with an appropriate hammer; do not substitute ordinary wrenches or pipe wrenches;
- Keep full face contact between hammer and struck block to avoid glancing blows that damage threads and openings;
- Wear eye and face protection per ANSI Z87.1; confirm bystander clearance before striking;
- Never attach a pipe or other “cheater” extension to increase leverage — over-torque fractures the wrench;
- Retire any wrench showing cracks, chipped faces, or distorted openings.
🚨 A fractured striking wrench throws fragments at high speed — shrapnel-equivalent. Never attach cheater pipes for over-torque, never strike with unsuitable hammers, and stop using any wrench showing cracks.
5. Engineering Practice Essentials 🛠️
- 🔍 Selection: choose wrench size by fastener size (opening dimension) and torque demand; confirm the opening matches the fastener to avoid slipping and rounding the hex.
- 🔧 Hammer pairing: use a hammer matched to the struck-face size; strike square and in full contact to avoid glancing blows.
- 📊 Series consistency: opening sizes follow the B107.6 / B107.9M (open-end/box wrench) and B107.17M gage systems, so products from different makers are interchangeable for opening checks.
- 📋 Inspection: inspect the struck face for dishing and chips and the opening for distortion before and after use; keep surfaces clean and slip-resistant.
6. Frequently Asked Questions ❓
❓ Q: What is the difference between a slugging wrench and a striking wrench?
A: Both are hammer-driven. The slugging wrench is a solid forged open-end wrench whose handle end is the struck face; the striking wrench is typically of box construction and transmits the blow through a struck block. The Standard provides separate nomenclature and struck-face design requirements.
A: Both are hammer-driven. The slugging wrench is a solid forged open-end wrench whose handle end is the struck face; the striking wrench is typically of box construction and transmits the blow through a struck block. The Standard provides separate nomenclature and struck-face design requirements.
❓ Q: Why is a dedicated “impact test” required?
A: The dominant load on these wrenches is impact, not static load. The impact test delivers the specified energy from Table 2 to the struck face, verifying fracture and spall resistance under real hammer-driven service — something a static check cannot replace.
A: The dominant load on these wrenches is impact, not static load. The impact test delivers the specified energy from Table 2 to the struck face, verifying fracture and spall resistance under real hammer-driven service — something a static check cannot replace.
❓ Q: May I add a cheater pipe for more force?
A: No. The Standard prohibits adding leverage devices — impact over-torque fractures the wrench directly, and the fragments fly at very high speed.
A: No. The Standard prohibits adding leverage devices — impact over-torque fractures the wrench directly, and the fragments fly at very high speed.
🔍 Q: How is wrench opening accuracy controlled?
A: Openings are controlled per the reference gage system of ASME B107.17M, ensuring fit with fasteners and consistency with the sizes of other wrenches in the series across manufacturers.
A: Openings are controlled per the reference gage system of ASME B107.17M, ensuring fit with fasteners and consistency with the sizes of other wrenches in the series across manufacturers.
