Read the cup stamp before you buy a hinge or a gas strut

A sagging HDB kitchen door is usually a Blum, Hafele or Excel cup hinge, or an AVENTOS lift that has lost its power factor. A like-for-like hinge set is S$90 to S$280. A gas-strut pair is S$120 to S$320. The job is permit-exempt carpentry. The wrong Newton rating, or a wood screw in stripped particleboard, is why the door drops again in a monsoon month.

The cup of a Blum Clip Top Blumotion hinge is stamped with the opening angle, commonly 110 degrees or 155 degrees, and with the boss pattern that the mounting plate has to match. Hafele and Excel cups look similar and are not always interchangeable. A 155 degree hinge on a plate drilled for 110 degrees leaves the door proud of the gable or makes the soft-close cam miss. Integrated Blumotion is a damper in the cup. A hinge without it slams, and a second clip-on damper is a different part number. Count the hinges. A 720mm door with two cups that have ovalled their holes needs three hinges or a repair plate, not a tighter screw.

AVENTOS HF, HK-S and HK-XS lift systems are not gas struts. The power factor is cabinet height in millimetres times door weight in kilograms, and that number picks the lift mechanism. A gas strut on a flap that used to be an AVENTOS is a different geometry. Where the door really is a strut, the Newton rating is printed on the tube: 60N, 80N, 100N, 120N or 150N. Too little and the door falls on the person cooking. Too much and the mounting screws tear out of particleboard. In an HDB kitchen the board is often 16mm particle with a melamine face. Once the screw spins, a longer screw into the same hole makes a larger hole. A stainless repair plate shifts the fastener into sound fibres and lets the correct strut stay.

Humidity at 80 percent does not rust a Blum nickel cup overnight, but it swells the particleboard around the screw and it softens the edge where a dishwasher has steamed the gable. That is why a hinge job and a carcass job are priced apart and can share a visit. Replacing every door because two cups are loose is the quote this page is written to stop. The cabinet repair versus replace calculator is the check when the base is also soft.

Homey Furnishing Pte. Ltd. (ACRA UEN 202018148K), 27 Mandai Estate, #06-10 Innovation Place, Singapore 729931, carries the permit-exempt portion of this work. V On Construction Pte. Ltd. (ACRA UEN 201611708H), listed on the HDB Directory of Renovation Contractors, carries any scope that needs an HDB renovation permit. Those two invoices are not interchangeable. Hardware replacement does not change the kitchen layout and does not need an HDB renovation permit. If the gable is so far gone that the box must be rebuilt, that is still usually permit-exempt carpentry unless the layout or a service riser changes.

Spend ten minutes with a torch, your phone camera, and a tape before you buy a product or book a hack. Write down what you see. The safe checks below do not ask you to open a live wire, cut a pressurised pipe, or lean out of a window. Photograph the stamp in the cup, the plate screw spacing, and the Newton figure on any strut. Weigh is not required if the old code is still readable. If the code is gone, measure door height and note whether the door is solid or an aluminium frame.

Stop at the red-flag column. Stop if an overhead door will not stay open, if the particleboard crumbles, or if you cannot read whether the system is a strut or an AVENTOS arm. The reason DIY fails is almost never a lack of effort. It is that the tool or chemical makes the next professional repair harder, or it hides a leak, a live conductor, or a deposit line until the damage is larger than S$90 to S$320 for hinges or a gas-strut pair.

This is the sequence a careful technician uses so you can tell a shortcut from a finished job. Tools stay in the van. Readings and photos go on the same worksheet as the price. A 35mm hinge cup is not re-drilled if the old cup still fits. The kit is the correct hinge or strut, a stainless repair plate when the hole is oval, a Pozi driver, and a square so the door gaps stay even.

1. Step 1. Make the area safe and confirm the symptom still matches the photos. For Read the cup stamp before you buy a hinge or a gas strut, that means Stop if an overhead door will not stay open, if the particleboard crumbles, or if you cannot read whether the system is a strut or an AVENTOS arm.
2. Step 2. Measure before touching the finished surface. Photograph the stamp in the cup, the plate screw spacing, and the Newton figure on any strut. Weigh is not required if the old code is still readable. If the code is gone, measure door height and note whether the door is solid or an aluminium frame.
3. Step 3. Set protection and lay out the tools that belong to this material. A 35mm hinge cup is not re-drilled if the old cup still fits. The kit is the correct hinge or strut, a stainless repair plate when the hole is oval, a Pozi driver, and a square so the door gaps stay even.
4. Step 4. Carry out the repair in the order the material allows. the new hinge angle or the Newton rating does not match, and the screw goes back into a stripped hole is the failure this order is written to avoid.
5. Step 5. Test in place. Each door closes on the damper, stays open where a strut should hold it, and the gaps are even. The old part numbers are written on the invoice so the next replacement matches.
6. Step 6. Clean, label the photographs against the invoice lines, and leave the statutory openings, weep holes, access panels and labels visible.

The order matters because the new hinge angle or the Newton rating does not match, and the screw goes back into a stripped hole is what happens when a step is rushed. Handover is a measurement, not a handshake. Each door closes on the damper, stays open where a strut should hold it, and the gaps are even. The old part numbers are written on the invoice so the next replacement matches. If the reading or the water test fails, the visit is not closed and a second line is priced before anyone leaves. Permit work, if the diagnosis has moved into hacking, waterproofing, or a new layout, stops here and is repriced through V On Construction Pte. Ltd. UEN 201611708H.

Hinges are priced per door set. Struts are priced as a pair because one new strut beside one old strut twists the flap. Prices below are 2026 Singapore bands for the described scope. They are not a coupon and they are not a guess after an unopened door. A second trade, such as a PUB licensed plumber or an EMA licensed electrician, is named when the law requires it rather than buried inside the labour line. Compare rows by what they include. The planning-life column belongs to that row only.

2026 SGD scope bands

Brand, material and lifespan

A repair plate is S$15 to S$40 per hole cluster and is cheaper than a new door. Book it with the cabinet repair service and check the repair-versus-replace calculator before a full kitchen quote.

Three worked jobs show how the same symptom is priced differently in a new BTO, an older resale flat, and a private condo or landed house. The totals are the lines a household actually paid, not a national average. Permit-exempt invoices are issued by Homey Furnishing Pte. Ltd. UEN 202018148K.

Case 1: 4-room BTO in Tengah

Four Blum 110 degree cups had lost Blumotion. The stamps were readable. Eight hinges and plates, no new doors, S$240. Ninety minutes. The particleboard was still tight.

Case 2: 28-year resale flat in Toa Payoh

Two overhead flaps used 80N struts that had leaked. The screws were spinning. Stainless repair plates and a pair of 100N struts, because the doors had been replaced with heavier ones, came to S$290. The AVENTOS question was checked and ruled out from the arm geometry.

Case 3: 2-bed condo in Katong

A tenant had forced a 155 degree hinge into a 110 degree plate. The door hit the gable. Correct 110 degree Blumotion hinges and a plate reset were S$160. The deposit line was the hinge, not a new kitchen.

Book the hardware on the cabinet repair page. Use the repair-versus-replace calculator if the photos also show a soft base. Send the photos and the measurements from the ten-minute check. The reply prices the band on this page against what the photos actually show.

• Book hinge and strut replacement
• Cabinet repair versus replace calculator
• When the carcass is the real problem

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