Blum hinge overlay or inset
Updated: 23 October 2026
You close the cupboard and the door sits in the wrong place. A Blum hinge overlay or inset choice is the arm. Straight-arm 71B3550 is full overlay. Full-crank 71B3750 is inset. The [Blum hinges comparison](/hub/diy-supplies/blum-hinges) lists the packs on amazon.co.uk. This page keeps to that one distinction. Peter F., editor for DIY & tools, used Blum's specification sheets and those listings. This is not a workshop test. A qualifying purchase through our links can earn us a commission at no extra cost to you.
You close the cupboard and the door sits in the wrong place. A Blum hinge overlay or inset choice is the arm. Straight-arm 71B3550 is full overlay. Full-crank 71B3750 is inset.
You close the cupboard and the door sits in the wrong place. A Blum hinge overlay or inset choice is the arm. Straight-arm 71B3550 is full overlay. Full-crank 71B3750 is inset. The Blum hinges comparison lists the packs on amazon.co.uk. This page keeps to that one distinction. Peter F., editor for DIY & tools, used Blum's specification sheets and those listings. This is not a workshop test. A qualifying purchase through our links can earn us a commission at no extra cost to you.
Our top picks
| Badge | Product | Application | Opening | Plate | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Blum Blum 8-pack with plates | Full overlay, frameless | 110° | Included | 9.2 | about £40.99 | View offer |
| Best value |  Blum Blum 8-piece overlay BLUMOTION | Full overlay | 110° | 173L8100 on the model line | 9.0 | about £27.48 | View offer |
| Alternative |  Blum Blum inset BLUMOTION 8-pack | Inset, frameless | 110° | Included, with cover plates | 8.8 | about £44.99 | View offer |
On this page
Where the door sits
Close the door and look at the carcass edge, not at the round cup. On a full-overlay door the front covers the side panel. On an inset door the front sits inside the opening, with carcass visible around it.
Blum's sheet for 71B3550 classes the hinge as a straight arm: screw-on, 110°, a 35 mm cup about 13 mm deep. The sheet for 71B3750 calls the cranking inset, with the same angle and cup. Collision height is 39.5 mm on the inset sheet and 21.5 mm on the overlay sheet. That extra metal is the bend. Side adjustment leaves the pressed shape as it left the factory. Cup drilling sits on the how to fit Blum hinges page.
71B3550 and 71B3750
71B3550 is the straight-arm overlay hinge. 71B3750 is the full-crank inset hinge. Both sheets use a 35 mm cup about 13 mm deep and a boring distance of 3–7 mm, so the hole will not sort them. Match the stamped number, or the bend, to the old arm.
Overlay packs here are the 71B3550 and 71MB3550 family. Paying for a plate does not put the door inside the opening. The Blum hinges buying guide sorts plates and screws. Inset in this set is pair B07C9CT26M, model 71MB3750, at £12.95, and eight-pack B077VQF8XC at £44.99. Reviews on the eight-pack say the crank was not obvious on the listing. They are the wrong spend when the door covers the side.
Half overlay is a different hinge
Half overlay is a third arm, 71B3650, for two doors that share one partition and each cover only part of that upright. A straight arm lets one door overlap its neighbour. A full crank pulls both doors back, so carcass shows where the old doors met.
This set does not clearly list a half-overlay ASIN. A title that says overlay still means 71B3550 unless the model line says 71B3650. If your doors meet on one upright, buy 71B3650 where that number is printed. A deeper 35 mm hole will not change the arm.
Which arm to buy
If the closed door covers the carcass side, stay with a straight arm. If it sits inside the opening, stay with a full crank. If two doors share one upright, stop and leave this set. Drill only after the arm in your hand matches the door you just closed.
Common questions
How do I tell overlay from inset on the cupboard?
Close the door and look at the carcass side. When the door face covers that side, you have full overlay and a straight arm, 71B3550. When the door sits inside the opening with carcass visible around it, you have inset and a full crank, 71B3750. The cup is 35 mm either way, so the hole will not separate them. Take the old hinge off and match the bend before you order.
What is a straight arm versus a full crank?
A straight arm, 71B3550, holds the door in front of the side panel. A full crank, 71B3750, sets the door back into the opening. Blum's sheets name those crankings full overlay and inset. The inset sheet lists a collision height of 39.5 mm, against 21.5 mm on the overlay sheet. Side adjustment moves the door on that arm and leaves the pressed shape as it was made.
Which model number is which?
71B3550 and the 71MB3550 packs here are full overlay. 71B3750 and the 71MB3750 pair are inset. 71B3650 is half overlay, and this set has no clear listing for it. Reviewers of eight-pack B077VQF8XC said the listing left the crank unclear. Match the stamped number, or the old arm, rather than the word Blum alone. A different plate in the box does not change the number on the arm.
Can I adjust a straight-arm hinge until the door sits inset?
The screws move the door in height, side, and depth on the arm you fitted. They leave a straight arm straight, so an inset door needs 71B3750. In this set that is pair B07C9CT26M at £12.95, or eight-pack B077VQF8XC at £44.99 when several inset doors match. Forcing a 71B3550 usually makes the door bind or sit proud of the next door. Get the crank right before those screws are worth turning.
What is half overlay, and is it in this set?
Half overlay is hinge 71B3650, for two doors that share a partition and each cover only part of it. The arm is a half crank, between the straight arm and the full crank. This amazon.co.uk set has no clear 71B3650 listing, so the 71B3550 and 71B3750 packs are the wrong parts. Buy 71B3650 where that number is printed. Keep this comparison for doors that cover the side or sit fully inside.
Why did an inset pack not fit my overlay door?
An inset pack is a full crank, so on a door that should cover the side it holds the door back. You see carcass, and the door misses the line of the neighbouring overlay doors. Reviews of the £44.99 eight-pack B077VQF8XC say the crank was not obvious. Check 71B3750 against 71B3550 before you drill. The cup is still 35 mm, so the hole can be right while the arm is wrong.
Related pages
Sources
Public sources from the research digest, plus the amazon.co.uk listings compared on this page. Prices were captured on 19 October 2026. Updated 23 October 2026.
- Blum UK, CLIP top BLUMOTION (retrieved 22.10.2026)
- Blum, number of hinges (retrieved 22.10.2026)
- 71B3550 specification sheet (retrieved 22.10.2026)
- Blum catalogue, mounting plates (retrieved 22.10.2026)
- BS EN 15570:2008 via NBS (retrieved 22.10.2026)
- GOV.UK, General Product Safety Regulations 2005 (retrieved 22.10.2026)
- DIYnot thread on 71B3550 (retrieved 22.10.2026)
- Hart Wholesale on the 60° bi-fold (retrieved 22.10.2026)