Needle scaler HAVS calculator Estimate daily hand-arm vibration exposure from needle scalers using HSE data. Choose the type and enter actual tool-use time. Add other tools used by the same person to calculate total exposure points.
- Free to use
- No account needed
- Based on HSE-published data
- Nothing is stored
Work out one person's daily exposure
One person, one day. Add each vibrating tool they use and how long it is in use.
Not counted yet: type not chosen.
Daily exposure
No result yet
Not counted yet: Needle scaler (type not chosen).
About this estimate
Based on HSE-published data (HSE, Vibration risk assessment, Table 1 "Some typical vibration levels for common tools", read 16 September 2026). HSE has not reviewed or endorsed this calculator. An estimate to support an exposure assessment, not a measurement, a risk assessment or a compliance certificate.
Needle scaler vibration values
HSE publishes 2 figures for needle scalers, so the calculator asks which type: not vibration reduced (12 to 26 m/s², starting value 19); vibration reduced (3 to 8 m/s², starting value 7).
At the starting values, not vibration reduced reaches the exposure action value after about 8 min and the limit value after about 33 min; vibration reduced takes about 1 h 1 min to reach the action value.
Needle scaler is a hammer-action tool. HSE's rule of thumb is that hammer-action tools are likely to pass the action value after about 15 minutes a day and the limit value after about an hour.
Also known on site as: needle gun, descaler.
The estimate uses HSE's category figure; the range uses the published range. Start with a blank calculator to choose different tools.
What it works out
One person's daily hand-arm vibration exposure, called A(8): the vibration from every tool they use, weighted by how long each is in use, averaged over an eight-hour day. It is shown in HSE's exposure points, where 100 points is the exposure action value and 400 points the exposure limit value, and in m/s² A(8) under "Show more".
Each tool's share is its vibration figure multiplied by the square root of its hours divided by eight. Tools combine as the square root of the sum of their squares, which is why one heavy tool for a short time can matter more than several light ones. Points are 2 × figure² × hours and simply add up.
Where the vibration figures come from
From HSE's vibration risk assessment guidance, which publishes a range and a typical figure for common tool categories, measured in real use. The calculator asks for the type of tool only where HSE publishes different figures, for example a 100 mm grinder against a 230 mm one, or a needle scaler with and without vibration reduction.
The estimate uses HSE's figure for the category. The range shows the day recalculated with the bottom and top of each published range. Tools within a category vary, and whether a tool is battery, corded or air-powered does not by itself say where it falls. If you have a better figure for a particular tool, enter it and it is used as given.
What the action and limit values mean
- Exposure action value, 2.5 m/s² A(8), 100 points. At or above it, the employer must reduce exposure as low as reasonably practicable with organisational and technical measures, give information and training, and provide health surveillance for regularly exposed workers.
- Exposure limit value, 5 m/s² A(8), 400 points. Must not be exceeded. If it is, exposure must be brought below it at once and the cause found and fixed.
- Below the action value the duty to keep exposure as low as reasonably practicable still applies. Some people are affected below it.
The values come from the Control of Vibration at Work Regulations 2005. HSE's advice for employers and its brief guide (INDG175) set out what to do at each level.
What it does not do
- It does not measure anything. It estimates from published category figures, and real exposure can be outside the range shown.
- It is not a risk assessment or a compliance certificate, and a result below the action value is not a guarantee of safety.
- It covers hand-held and hand-guided tools only: no vehicles, no whole-body vibration, no noise.
- It does not hold a catalogue of makes and models. For a specific tool, use the value from its handbook, allowing for real use, or a measurement.
- It works for one person's day. A weekly average and other special cases in the Regulations are outside it.
It uses the same arithmetic as HSE's own exposure calculator, which remains available for those who prefer a spreadsheet.
Start with a tool
Open the calculator with a tool already chosen and HSE's figures for it explained.
- Drill
- Impact wrench
- Stapler
- Angle grinder
- Die grinder
- Straight grinder
- Pedestal grinder
- Cut-off saw
- Reciprocating saw
- Jigsaw
- Nibbler
- Sander
- Polisher
- Router
- Breaker
- Demolition or rotary hammer
- Pneumatic hammer
- Chipping hammer
- Stone hammer
- Rock drill
- Scabbler
- Needle scaler
- Plate compactor
- Water jetting gun
- Brushcutter or strimmer
- Chainsaw
- Hedge trimmer
- Hand-guided mower
Questions people ask
- Is this the same as the HSE calculator?
- It uses the same arithmetic and the same published category figures, and it shows exposure both in m/s² A(8) and in HSE exposure points. HSE has not reviewed or endorsed it. It adds the things a busy supervisor needs: the vibration figures filled in, a range as well as a single number, and a link or PDF to pass on.
- What time do I enter?
- The time the tool is actually running with the worker's hands on it, sometimes called trigger time, added up over the day. Leave out breaks, walking, setting up and waiting. People overestimate this, so timing a few minutes of the job and scaling up is better than a guess.
- What if the tool is not in the list?
- Choose "Something else" and enter a vibration value in m/s² from the tool's handbook, a supplier's declaration or a measurement. Handbook figures often understate real use, so HSE suggests allowing a margin. Do not pick a category that only sounds similar: a nail gun is not a stapler, and HSE publishes no figure for it.
- Why is there a range?
- HSE publishes a range for each category because tools, materials and technique vary. The estimate uses HSE's recommended starting value; the range shows where a day with the same tools could fall. Real exposure can be outside it. It is not a guaranteed bound or a statistical confidence interval, but when it crosses a threshold the calculator says so.
- Does a green result mean we are compliant?
- No. Green means the estimate is below the exposure action value. The employer still has to keep exposure as low as reasonably practicable, and this is an estimate from published averages, not a measurement. It supports an exposure assessment; it is not a risk assessment or a certificate.
- Is the calculation for the whole crew?
- No. It is one person's day. If three people share a breaker, work out each person's own time on it. If the pattern changes from day to day, run the busiest day.
- Is anything saved?
- No. The calculation lives in the link itself, so anyone with the link can open it, and nothing is stored by ComplyOnSite. Changing a shared calculation makes a new link; the original stays as it was.