How to use a terminal block
Updated: October 2026
You have an existing, accessible joint, and a 12-way choc strip in your hand. This is how to use a terminal block of that screw-strip kind: prove the circuit is dead, cut only a strip that is meant to be cut, put one conductor in the hole, tighten until it grips, tug, and leave the joint in a box. Rankings stay on the [terminal block comparison](/hub/diy-supplies/terminal-block). UK mains are 230 V. No torque is printed for these strips, so this page does not invent one. Peter F. checked the amazon.co.uk listings on 16 October 2026. There was no laboratory joint test. Links to amazon.co.uk from the comparison are affiliate links.
You have an existing, accessible joint, and a 12-way choc strip in your hand.
You have an existing, accessible joint, and a 12-way choc strip in your hand. This is how to use a terminal block of that screw-strip kind: prove the circuit is dead, cut only a strip that is meant to be cut, put one conductor in the hole, tighten until it grips, tug, and leave the joint in a box. Rankings stay on the terminal block comparison. UK mains are 230 V. No torque is printed for these strips, so this page does not invent one. Peter F. checked the amazon.co.uk listings on 16 October 2026. There was no laboratory joint test. Links to amazon.co.uk from the comparison are affiliate links.
Our top picks
| Badge | Product | Cut | Bullet length | Clamp | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  GTSE GTSE 3 A and 15 A strip pack | In reviews, not the bullet | n/a | Screw | 8.7 | about £7.99 | View offer |
| Preis-Tipp |  Blackspur Blackspur BB-CT110 3 A and 15 A | In reviews, not the bullet | n/a | Screw | 7.2 | about £3.60 | View offer |
| Alternative |  LTMMC LTMMC 3 A, 5 A and 10 A strips | Bullet says cut | About 10 mm | Screw | 4.7 | about £4.99 | View offer |
On this page
Prove the circuit is dead first
Start at the consumer unit, not at the screw. Identify the circuit, switch it off, and lock it if you can. Prove it dead with a contact voltage detector, on line, neutral and earth. HSE’s GS38 is the point: a contact instrument proves dead, and a non-contact stick only suggests something may be live. Prove the tester before and after, so a dead reading is not a flat battery.
Electrical Safety First’s Best Practice Guide 2 uses the same order. If you cannot prove the circuit is dead, stop. A new circuit, a consumer unit, or a bath or shower zone is not this procedure. The terminal block for lighting page sets out England’s notification line.
Cut only a strip that is meant to be cut
XINXINGDINGSHENG says scissors or a knife. Funver and LTMMC say the strip can be cut. HSEAMALL’s bullet is about cutting the jumpers, not sawing the barrier body. GTSE, Blackspur and the SDFIXINGS 3 A listing do not say cut in the bullet. UK reviews say those strips can be cut. A review is what buyers did, not a maker’s instruction.
Cut between the ways, on the moulded bridge, rather than through a brass tunnel. Do not saw a lever splice. If the body cracks, bin that piece. Blackspur reviews describe housings that crack, and XINXINGDINGSHENG reviews describe plastic that exposes metal.
Strip, insert one conductor, tighten, tug
Strip only as far as the copper needs to fill the tunnel. flintronic’s bullet mentions about 9–10 mm, and LTMMC’s bullet says about 10 mm. Those lengths belong to those bullets. Where the page is silent, the insulation should meet the hole. These packs do not include ferrules.
One conductor per hole unless the maker says otherwise. No torque is printed here, so do not copy a figure from another product. Tighten until the wire does not swivel, and stop when the brass splits or the screw cross-threads. That is the review failure on the SDFIXINGS 3 A strip, LTMMC, Blackspur and XINXINGDINGSHENG. Then tug the conductor along its length, with the circuit still dead. If the wire comes out, replace the piece.
The joint still needs a box
Tape is not the enclosure. HSE says not to repair a cable with tape or an unsuitable connector. No capture prints an IP rating, so you do not leave the strip outdoors and you do not bury it. The rose, or a proper box, is what surrounds the joint.
A lever does not skip this step. These listings do not claim a maintenance-free accessory you can hide. The terminal block versus lever connector page sets that limit. If the cover will not close without crushing the strip, you have cut too many ways, or you have the wrong connector for the space.
When you stop
Stop if you cannot prove the circuit is dead, if the cable is scorched, or if the brass has split. Stop if the hole will not take the conductor without doubling up. Stop and call an electrician for a new circuit, a consumer unit, or a bath or shower zone. In England those are the notifiable jobs in Approved Document P. A bedroom rose on an existing circuit is a different case, and it still has to be safe. The terminal block buying guide is where you check the amp cell before you start.
Common questions
What do you do before you open the fitting?
Switch off at the consumer unit and prove the circuit dead with a contact voltage detector, on line, neutral and earth. Prove the tester before and after, as HSE GS38 and Electrical Safety First’s Best Practice Guide 2 describe. A non-contact stick does not prove dead. UK mains are 230 V. If you cannot get a proved dead reading, leave the rose closed and call an electrician.
How do you cut a 12-way strip?
Cut between the ways, and only when a bullet or a clear review pattern says the strip is meant to come apart. Bullets that say cut include XINXINGDINGSHENG, Funver and LTMMC. HSEAMALL’s bullet is about cutting the jumpers. GTSE, Blackspur and the SDFIXINGS 3 A strip are described as cuttable in reviews, not in the bullet. Do not cut a lever splice. If the body cracks, discard that piece.
How tight is tight enough if no torque is printed?
Tight enough that the conductor does not swivel, and not so tight that the brass splits or the screw strips. No torque is printed for these twelve listings, and figures from other products should not be copied across. UK reviews describe stripped screws, split brass, shredded plastic and cross-threaded screws. If the thread is already gone, another turn will not fix it.
What is the tug for?
The tug tells you the screw or the spring is holding, while the circuit is still dead. Pull along the wire. flintronic reviews say a wire can pull out unless you tug it, and some levers snap. The same check belongs on a choc strip. If the conductor comes out, remake the joint on a sound piece. A tug is not a substitute for proving the circuit dead, and it is not a load test at 230 V.
When do you stop and call an electrician?
Call an electrician if you cannot prove the circuit is dead, if the cable is scorched, if you are adding a new circuit or changing a consumer unit, or if the fitting is in a bath or shower zone. Replacing a cracked piece is still your job only on an existing joint you can prove dead. The lighting page sets out when that work is notifiable in England.
Related pages
Sources
Public UK sources on electrical safety and household connecting devices. Listings checked 16 October 2026. Prices on amazon.co.uk move.
- Approved Document P (2013) (retrieved 16 October 2026)
- Building Regulations 2010, Schedule 1, Part P (retrieved 16 October 2026)
- Planning Portal, electrics and building regulations (retrieved 16 October 2026)
- HSE, electrical equipment (retrieved 16 October 2026)
- BS EN 60998-1, household connecting devices (retrieved 16 October 2026)
- BS EN 60998-2-1, screw-type clamping units (retrieved 16 October 2026)
- GOV.UK, UKCA and CE marking in Great Britain (retrieved 16 October 2026)
- IET, BS 7671 18th Edition (retrieved 16 October 2026)