Struck Hands and Flogging Spanners: How to Keep Hands Away from the Impact Zone

Flogging spanner work is one of the most predictable hand injury tasks in industrial maintenance — the hand is always near the striking point, the hammer blow is intentional, and a miss of a few centimetres causes a serious injury. The question is what replaces the hand that holds the spanner.

The problem with holding a flogging spanner

A flogging spanner — also referred to as a slogging spanner in Australian industry — is an open-ended or ring spanner designed to be struck with a hammer or sledge to apply high torque to large fasteners that cannot be reached with a torque wrench or power tool. They are a standard item in mining maintenance, oil and gas well servicing, flange work, pipeline maintenance, and heavy engineering.

The way they are conventionally used creates a direct hand-injury risk. One worker holds the spanner on the fastener. A second worker strikes the opposite end of the spanner with a hammer. The holding hand is typically 100–200 mm from the point where the hammer strikes. At that distance, a miss of a few centimetres means the hammer lands on the hand or fingers.

This is not a theoretical risk. It is one of the most common serious injury mechanisms in the Australian resources sector. Queensland's Resources Safety and Health Queensland data for the period 2007–12 recorded that lacerations, cuts and other open wounds (25%) and fractures (30%) together accounted for 55% of all serious hand injuries in Queensland mining over five years, with a further 9% being traumatic amputations. "Hit by moving objects" was identified as the second most common mechanism of serious hand injury (19%), and maintenance activities accounted for over half of all serious hand injuries reported in that period.

NSW Resources Regulator Safety Bulletin SB24-04 (July 2024) noted that among the 50 hand and finger injury reports received over two years, multiple incidents involved machinery contact and struck-by mechanisms. The broader pattern of NSW mining hand injuries — consistently 33% or more of all serious injuries across multiple years of reporting — reflects a population of injuries that includes both struck-by events and caught-between events, many of which occur during maintenance tasks.

Flogging spanner work sits squarely in both categories: the hand can be struck by the hammer (struck-by), and if the spanner slips off the fastener during the strike, the hand between the spanner and an adjacent structure can be caught between (caught-between).

Why gloves do not solve this

The almost universal safety response to flogging spanner work is impact-resistant gloves. Impact gloves — those with dorsal padding across the knuckles and fingers — are a genuine improvement over unprotected hands when the contact is a glancing blow or a low-energy impact. They absorb some of the force of a misdirected strike.

They do not, in practice, prevent a direct hammer blow to a finger from causing a serious injury. A hammer weighing 2–4 kg, swung with reasonable force, carries far more energy than any currently available glove can fully absorb at the point of impact.

NSW Resources Regulator Safety Bulletin SB22-04 (March 2022) observed that workers "were wearing gloves in most incidents" in the 141 hand injury reports it reviewed. The gloves did not prevent the injuries. This is consistent with the hierarchy of controls principle: PPE is the last layer of defence, not the primary control. Where the hazard is a direct, predictable, high-energy impact, the primary control should be reducing the likelihood that the impact occurs on the hand — not relying on the glove to limit the damage if it does.

What the actual hand exposure is

To apply the Find The Hand™ discipline to flogging spanner work, it helps to be precise about what the hand is doing and why it needs to be there.

The holding hand performs two functions:

1. It holds the spanner on the fastener — keeping the spanner head engaged with the nut or bolt head during the strike, so that the strike force translates into torque on the fastener rather than driving the spanner off sideways
2. It stabilises the spanner against rebound — after the hammer lands, the spanner tends to bounce. The holding hand damps this rebound so the spanner stays on the fastener for the next strike

Both of these functions place the hand within the striking zone — close enough to the spanner end to be at risk from a misdirected or deflected hammer blow.

The question the Find The Hand™ approach asks is: can either of these functions be performed by something other than a bare hand positioned that close to the impact?

The PSC Fingersaver and HSF WrenchGrab — what they do and how

The PSC Fingersaver and the HSF WrenchGrab are tools designed to hold a flogging spanner in position on a fastener while keeping the worker's hand several hundred millimetres further from the strike end than conventional hand holding allows.

The principle is straightforward: the tool attaches to or supports the spanner shaft at a point well away from the impact end, and the worker grips the tool — not the spanner — from a position that puts their hand outside the hammer's likely strike zone.

PSC Fingersaver

The PSC Fingersaver is available in three sizes — PSC-FS-295 (295 mm), PSC-FS-350 (350 mm), and PSC-FS-850 (850 mm) — to suit different fastener sizes and spanner lengths. The tool holds the spanner in position on the fastener while the worker's hand grips the Fingersaver body, which extends the hold point back along the spanner shaft. The 850 mm version is designed for two-person use on large fasteners where the spanner requires significant steadying force.

HSF WrenchGrab

The HSF WrenchGrab is the HSF-branded variant designed for workshop, maintenance, and engineering environments. It serves the same function as the PSC Fingersaver — extending the hold point away from the impact zone — and is suited to workshop and site maintenance applications across mining, engineering, and power generation.

These tools do not eliminate the risk of a direct, catastrophically misdirected hammer blow — no tool short of full mechanical isolation of the fastener does that. What they do is move the worker's hand out of the zone where a normally misdirected strike would land, changing the outcome of the most common miss from a finger fracture or crush to a strike on the tool body.

Other controls that reduce striking-tool hand exposure

The Fingersaver and WrenchGrab address the specific task of holding a flogging spanner during a strike. Other controls that reduce hand exposure in striking and fastener work more broadly include:

Task substitution where available

If the fastener can be reached with a hydraulic torque wrench, a pneumatic impact wrench, or a powered tensioning tool, the flogging spanner task should not be specified. Powered tools remove the person-strikes-hand scenario entirely. Flogging spanner work is the task of last resort for large fasteners — it should be used where powered tools cannot access the fastener or cannot provide sufficient torque, not as a first-choice method.

Correct spanner and hammer selection

A spanner that does not seat correctly on the fastener head, or a hammer that is too heavy for the confined space in which the strike is happening, increases the likelihood of a miss or a deflection. Both the spanner and the hammer should be appropriate for the specific fastener and the working geometry.

Two people — communication and timing

When two people are required — one holding, one striking — clear communication about strike timing is a basic control. The holder signals readiness; the striker does not proceed until the signal is given. A system where the striker acts without a signal from the holder is a system that will eventually produce a holding hand that is not ready when the hammer lands.

Lighting and access

Flogging spanner work in poor light or awkward body positions — which is typical on mine sites — increases the probability of a miss. Where possible, adequate lighting should be confirmed before the task begins, and the worker striking should have a clear, comfortable swing path that does not require contorting around other equipment or personnel.

The regulatory context

NSW Resources Regulator Safety Bulletin SB24-04 (July 2024) recommends that mine operators "involve workers to identify pinch/crush points and identify solutions to control the hazard." Flogging spanner work is a task that workers on any mining or maintenance site will identify immediately as a hand-exposure risk — it is one of the most visceral and obvious risks in routine maintenance. The Bulletin's recommendation to find solutions and work through the hierarchy of controls applies directly to it.

The hierarchy does not prescribe a specific answer. It asks the question in order: can the exposure be eliminated? Can it be substituted? Can it be reduced by an engineering or administrative control before reaching PPE? For flogging spanner work, the sequence of controls looks like this:

• Eliminate — use a powered torque or tensioning tool instead of a flogging spanner wherever possible
• Substitute — use a longer spanner or a different tool configuration that moves the striking point further from the holding point
• Engineering control — use a spanner-holding tool (PSC Fingersaver, HSF WrenchGrab) that moves the holding point away from the impact zone
• Administrative control — two-person communication protocol; lighting confirmation; correct tool selection
• PPE — impact-resistant gloves as the final layer

The industry's current default — impact gloves plus a verbal instruction to be careful — sits only at the bottom two levels of that hierarchy. Moving up to the engineering control level — a spanner holder that changes where the hand is — is a proportionate and practical response to one of the most common and predictable hand injury mechanisms in Australian mining and heavy industry.