The classic snap-off job. Heat the nut, not the stud: the nut expands, the corrosion in the thread lets go and the nut turns off with the stud still in place.
Working method
Loosen seized bolts without a torch
A rusted bolt does not need more force — it needs heat in the right place. With an induction heater you heat the fastener itself in seconds, the rust lets go and the bolt turns out undamaged. No flame, no scorched paint, no broken stud.
Why heat works
Heat where the connection is stuck
Rust, corrosion and thread-locker wedge a bolt in its thread. Pulling harder rounds the head, snaps the stud or damages the part around it — and every one of those costs more time than the bolt itself. Heat breaks the deadlock: the steel expands, the rust layer cracks and the thread-locker softens.
An induction heater puts that heat straight into the fastener. Slide the coil over, press the trigger, and within seconds the bolt is hot while the housing, hoses and wiring around it stay cold. Release the trigger and heating stops immediately.
- Seized nuts, bolts, studs and threaded connections
- Exhaust, suspension, brakes and driveline
- Safe next to wiring, hoses, fuel lines and trim
- Hot in seconds, no flame, no gas bottle
Step by step
Seized bolt out in five steps
1. Clean and look. Brush off loose rust and dirt and check what sits close to the fastener: fuel lines, rubber bushings, sensors. 2. Pick the coil. Choose the coil that fits closest around the nut or bolt head — a tight fit means fast heat. 3. Heat. Press the trigger for a few seconds until the fastener starts to take colour; on a thread-locked screw about 250 °C is enough.
4. Turn while hot. Remove the coil and put the spanner on straight away — the expanded steel and the cracked rust give the thread the clearance it needs. 5. Repeat if needed. A large or badly corroded bolt sometimes needs a second cycle. Heat again briefly rather than forcing it.
The fasteners that used to cost you an hour
Bolts seized in rubber-bushed sleeves and control-arm eyes. Heat the sleeve or bolt head in short bursts, well away from the rubber, and drive the bolt out instead of cutting it.
Caliper bolts, flywheel and pulley screws set with high-strength thread-locker. A few seconds of heat softens the compound and the screw comes out without rounding the drive.
The right coil makes induction fast
One coil per diameter, slid straight over the nut or bolt head. The closest fit and the fastest heat — the Professional Kit puts the whole set in the case.
Wrap it around anything a ring coil does not reach: large nuts, hubs, sleeves, bulky parts. Kevlar-protected up to 750 °C.
For fasteners you can only approach from one side — behind a bracket, under a flange, in a recess.
Everyday automotive fasteners: the W1200. Truck and machinery bolts or all-day use: the W2300 Power+. Not sure? Use our selector: Which iDuctor do I need?
The iDuctor range
Compare the three iDuctor systems
Open a system to compare the Basic and Professional kits, prices, specifications and compatible coils.
Popular kits
Go straight to the right system
Three proven setups for day-to-day workshop work, heavier heating jobs and maximum output.
Professional
See kit
1200W system
iDuctor W1200
The iDuctor W1200 Basic Kit is a compact induction heating kit for safely loosening rusted ferrous parts without an open flame. It combines the 1200-watt iDuctor W1200 with the essential coils and accessories for precise day-to-day workshop work.
Advanced+
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2000W system
iDuctor W2000 120V
The iDuctor W2000 Basic Kit 120V is a higher-output induction heating kit for heavier workshop jobs. This dedicated 120-volt version uses the W2000 platform to loosen rusted ferrous parts safely and precisely without an open flame.
Ultra Power++
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2300W Power+
iDuctor W2300 Power+ Kit
The iDuctor W2300 Power+ Kit is a high-output induction heating kit for heavier jobs. With 2300 watts of output, it safely loosens larger and heavier ferrous parts without an open flame and supports Flexcoils from 1100 mm up to 3500 mm.
About loosening seized bolts
How hot does a seized bolt need to be?
For rust, a dull glow is more than enough — often a few seconds. Thread-locker lets go from about 250 °C. Heat briefly, turn immediately; if the bolt does not move, heat again rather than forcing it.
Do I heat the bolt or the nut?
Heat the part you want to turn off. For a nut on a stud: heat the nut so it expands away from the stud. For a bolt in a threaded hole: heat the bolt head and the area around the thread so the whole connection expands and the rust cracks.
Does induction work on every bolt?
On every steel or cast-iron fastener — which is practically all of them. Aluminium and copper do not heat directly, so an aluminium housing stays cold while the steel bolt inside it heats.
Can I still use penetrating oil?
Yes, before or after heating, never on a red-hot part. Heat first, let the bolt cool a little, then apply oil: the cracked rust layer now lets the oil in.
Which iDuctor is right for seized bolts?
The W1200 covers everyday automotive fasteners. The W2000 120V does the same on a 120-volt supply. The W2300 Power+ heats truck bolts and massive parts and stands up to all-day use.
Continue with the right guide
Want to stop cutting and drilling out bolts?
Tell us which fasteners cost you the most time and we will recommend the iDuctor and the coils that free them in seconds.