Trelawny SF1 & SF3 scaling hammers for heavy scale and thick coatings
SF1 Vibro-Lo single head - 196.5095
Pneumatic percussion hammers that fracture heavy scale, thick paint and rust ahead of blasting or recoating. The single-head SF1 is 55 mm wide and 2.5 kg, built for the areas behind frames and up against bulkheads. The triple-head SF3 strikes with three pistons at once for faster production on open steel. Both come as standard tools or ATEX-certified -EX versions with beryllium copper heads.
✓SepcoTech is an authorised Trelawny distributor
One piston, two hands
Every figure on this page lives somewhere on the tool. Hover or tap a number to trace it to the hardware.
- 01Piston3,000 bpmOne 27 mm piston (612.5301) on a fixed 26 mm stroke. The tool weighs 2.5 kg.
- 02Front hand9.9 m/s²The higher of the two declared figures: about 31 min of trigger time to the EU action value.
- 03Cutter head55 mmWorking width of the taper-fit cruciform head, tungsten carbide tipped (426.5351).
- 04Throttle hand3.7 m/s²Measured at Trelawny's vibration-reduced Vibro-Lo main handle.
- 05Air inlet4.25 l/s (9 cfm)At 6.2 bar (90 psi). Size the compressor for 7.0 l/s (15 cfm) free air per single-head tool.
Models & Consumables
Pick the head type, then the exact model. Every tool, cutter head, piston, service kit and air-line accessory carries its genuine Trelawny part number, with the IMPA code where one is published, and adds straight to your quote. ShipServ TN 317548.
Authorised Trelawny distributor
The hardware, its warranty and its documentation are Trelawny's. The EUR quote with no hidden import costs, the consumables and the support in your time zone are ours. We supply genuine parts only, because Trelawny's warranty does not cover non-genuine consumables.
Which SF Hammer?
A scaling hammer does the first, aggressive pass: it breaks up hard, thick material that a needle scaler would take all day over. Start from the job.
SF1 Vibro-Lo
One piston, 55 mm wide and 2.5 kg. Trelawny build it for smaller, awkward areas that larger tools cannot reach.
196.5095
SF3 Triple Head
Three pistons side by side, 155 mm wide. Not quicker per blow, but it strikes three points on every pass. It has the highest vibration in the range.
153.5300II 2 G Ex h IIC T4 GbII 2 D Ex h IIIC T135°C Dbcertificate EMT19ATEX0020XVLSF1-EX or SF3-EX
ATEX certified, with spark-resistant beryllium copper heads. See what the certificate covers.
196.5110 · 153.5310no separate head
SF1 or SF3 Single Piece
Trelawny call it the economical option: nothing to change, but the whole piston is replaced when it wears. These models do not take the bush hammer head or any other taper-fit head.
196.5080 · 153.5380
Any taper-fit model + bush hammer head
Fit the bush hammer head in place of the cruciform. Trelawny describe it as leaving a heavier key.
426.5352
Not a scaling hammer
A rigid head does not follow a contour. A needle scaler does, because every needle moves on its own. The scaling hammer vs needle scaler guide covers where each tool works.
Most jobs need bothHow a Scaling Hammer Works
Compressed air drives a hardened piston onto a cutter head 3,000 times a minute. Each blow fractures the scale or coating it lands on.
The piston travels a fixed 26 mm stroke. On taper-fit models it carries a separate cutter head that wedges onto a taper at the tip. The head does the cutting and wears, so it is the part you replace. The operator only needs enough contact pressure to stop the tool bouncing off the surface. Trelawny's manual says that leaning on the tool does not make it work faster. It only wears it out sooner.
The three heads
Cruciform, carbide tipped426.5351The standard head, for fracturing and removing coatings.
Cruciform, beryllium copper606.5303The spark-resistant head. It is the only head permitted in the -EX tools.Bush hammer, carbide tipped426.5352Leaves a heavier key on the surface than the cruciform.Common piston, common heads. Every taper-fit SF1 and SF3 uses the same 27 mm piston, part 612.5301, and the same cutter heads, so stores hold one set of heads for both tools. The service kits are model-specific.
Changing a head on site
- Lay the tool head-up on a solid surface.
- Lift the old head off with the removal washer and pin.
- Clean both tapers with an oil-free solvent.
- Seat the new head with one sharp blow from a soft-faced hammer.
Vibration: Two Hands, Two Figures
Trelawny publish 3.7 m/s² for the SF1 in one place and 9.9 m/s² in another. Neither figure is a typo. They were measured at different hands.
The VLSF1-EX operation manual declares 3.7 m/s² at the throttle handle, which on the Vibro-Lo is Trelawny's vibration-reduced main handle, and 9.9 m/s² at the front hand on the tool body. The datasheet prints only the first figure and the product page the second, so the same part number circulates with both. Assess the hand that takes more vibration: on a scaling hammer that is the front hand, which is on the tool for the whole job.
What that means for the rota. Both SF hammers are burst tools. Plan rotations on the front-hand figure: about half an hour to the action value and two hours to the limit value. For long continuous work on open deck, look at the walk-behind SF11 deck hammer at 5.76 m/s², or at a Vibro-Lo needle scaler for detail work.
Full figures, including the +40% uncertainty rows
| Tool, grip | Vibration m/s² | Time to action value (2.5) | Time to limit value (5.0) |
|---|---|---|---|
| SF1 / VLSF1-EX, throttle hand | 3.7 | 3 h 39 min | beyond an 8 h shift |
| SF1 / VLSF1-EX, front hand | 9.9 | 31 min | 2 h 2 min |
| SF1, front hand at +40% | 13.86 | 16 min | 1 h 2 min |
| SF3 / SF3-EX, throttle hand | 13.4 | 17 min | 1 h 7 min |
| SF3 / SF3-EX, front hand | 12.0 | 21 min | 1 h 23 min |
| SF3, throttle hand at +40% | 18.76 | 9 min | 34 min |
SepcoTech's calculation from Trelawny's declared values, using T = 8 × (2.5 ÷ a)² hours for the 2.5 m/s² A(8) action value and the same formula with 5.0 for the limit value, both under Directive 2002/44/EC. The +40% rows are the top of the uncertainty range Trelawny state in the manuals. Trigger time, not shift length. The figures assume this is the operator's only vibrating tool that day.
VLSF1-EX and SF3-EX
The ATEX certificate covers the whole tool used under its conditions of safe use, not only the head.
Both -EX tools are certified under Directive 2014/34/EU to EN 60079-0, EN ISO 80079-36 and EN ISO 80079-37. The notified body is Element Materials Technology and the certificate is EMT19ATEX0020X, as printed in both operation manuals.
Reading the gas marking: II 2 G Ex h IIC T4 Gb
IIEquipment group II: surface industries, not mining2Category 2: suitable for Zones 1 and 2, or 21 and 22GGas atmospheresEx hNon-electrical equipment, EN ISO 80079-36/-37IICThe most demanding gas group, which includes hydrogen and acetyleneT4Surface temperature 135 °C maximumGbEquipment protection level b: highThe dust marking: II 2 D Ex h IIIC T135°C Db
DDust atmospheresIIICConductive dust, the most demanding dust groupT135°CSurface temperature 135 °C maximumDbEquipment protection level b for dustThe trailing X on the certificate number means there are special conditions of safe use. The manual lists them:
- A filter on the compressor intake, to keep dust and foreign material out of the air supply
- Carbonisation-resistant compressor lubricants, and tool oil with an auto-ignition temperature above 185 °C
- Anti-static air hose within the surface-resistance limit the manual states
- The painted surfaces are not to be exposed to charging stronger than manual rubbing
- The tool must not be stored in an acetylene atmosphere
- Only Trelawny beryllium copper heads. The manual is explicit: do not substitute any other head
Scaling Hammers: Common Questions
What is the difference between the SF1 and the SF3?
The SF1 has one piston and one cutter head, and the SF3 has three. The SF1 weighs 2.5 kg and works a 55 mm width, so it suits tight, awkward areas. The SF3 weighs 3.7 kg, works up to 155 mm wide and covers open steel faster because it strikes three points on every pass. The SF3 also reaches the vibration action value sooner: after about 17 minutes of trigger time, against about 31 minutes for the SF1.
Is the SF1 Vibro-Lo really 3.7 m/s² or 9.9 m/s²?
It is both. Trelawny's operation manual declares 3.7 m/s² at the throttle handle, which is vibration-reduced, and 9.9 m/s² at the front hand on the tool body. The datasheet shows the first figure and the product page the second. For an exposure assessment, use the higher hand: 9.9 m/s² puts an operator at the 2.5 m/s² action value after about 31 minutes of trigger time.
What size compressor does an SF scaling hammer need?
Trelawny's operation manuals specify at least 7.0 l/s (15 cfm) of free air per single-head tool and 12 l/s (25 cfm) per triple-head tool, at 6.2 bar (90 psi) at the tool. The tools consume 4.25 l/s and 5.2 l/s respectively, and the difference is the headroom the manual builds in. Add the tools together if more than one operator works from the same compressor.
Do I need the ATEX (EX) version?
Only where the work area is classified for potentially explosive atmospheres, for example Gas Zone 1 or Dust Zone 21 in a tank, hold, or a fuel or gas area. The VLSF1-EX and SF3-EX are certified II 2 G Ex h IIC T4 Gb and II 2 D Ex h IIIC T135°C Db under certificate EMT19ATEX0020X, with conditions of safe use. For open deck and general hull work, the standard tools are the right choice.
Can I fit a beryllium copper head to a standard SF hammer and use it in a gas zone?
No. The ATEX certificate covers the -EX tool as a whole, used under its conditions of safe use. It does not cover a head fitted to a standard tool. Use the VLSF1-EX or SF3-EX, and fit only Trelawny beryllium copper heads to them.
Can I change the cutter head on board?
Yes, on the taper-fit models. Trelawny's manual gives an on-site procedure: lift the old head off with the removal washer and pin, clean both tapers with oil-free solvent, and seat the new head with one sharp blow from a soft-faced hammer. If oil is left on the taper, the new head will not stay on. The Single Piece models have no separate head to change.
Can a scaling hammer clean welds?
Not well. A rigid head works on flat or gently curved plate. It does not follow the contour of a weld bead, flange or pipe joint. A needle scaler does, because every needle moves on its own. Most jobs need both tools.
Which SF parts carry IMPA codes?
Trelawny publish IMPA 59.03.84 for the SF1 Vibro-Lo single head (196.5095), 59.03.85 for the tungsten carbide cruciform head (426.5351) and 59.03.89 for the beryllium copper cruciform head (606.5303). Order the other parts by Trelawny part number. SepcoTech accepts RFQs on ShipServ under TradeNet 317548.
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