General Stainless Steel Hinge Series

A butterfly hinge — 子母 in Chinese, also called a mother-and-child hinge — has two leaves of different widths. The narrow leaf sits in the frame and the wide leaf carries the door, so the frame needs only a shallow mortise. A butt hinge has two leaves of equal width and needs a full mortise on both the frame and the leaf.

Choose butterfly where the frame is thin or where you do not want to cut deep into it; choose butt where both leaves are full width and you want the maximum load from the same leaf size. Both are the same price at the same size and thickness in this series, so the choice is a fitting decision, not a cost decision.

304 for anything that sees moisture, salt air or condensation — bathrooms, coastal buildings, unheated warehouses, exterior doors. 201 for dry interior doors in a heated building, where it performs the same and costs less.

The two are not interchangeable in a wet environment, and the failure is not immediate: a 201 hinge in a coastal bathroom looks fine at handover and then starts to show surface rust at the knuckle and around the screw holes. By then the building is handed over. If you are unsure which environment your order is going into, tell us the city and the building type and we will recommend one rather than quote both.

Height × width × leaf thickness. The first two figures are in inches, the third in millimetres: a 4 × 3 inch leaf that is 3.0 mm thick. The model number carries the same information in shorthand, with one letter in front for the shape — Z for butterfly, E for butt. So HY-Z-433 is a butterfly and HY-E-433 is a butt on that same leaf, because the last digit is the thickness code (3 = 3.0 mm, 5 = 2.5 mm, 4 = 4.0 mm).

So HY-Z-435 and HY-Z-433 are the same leaf at two different thicknesses, not two different sizes. This is worth checking on a competitor quotation, because a “4 inch hinge” on its own says nothing about the thickness, and the thickness is where the cost is. The letter matters just as much when you order: quoting HY-Z when the job needs a butt hinge gets you the wrong product in the right size.

45 kg per pair — two hinges, not one. Weigh the door leaf with its glass, its lock and its handles fitted, because that is the weight the hinges actually carry.

If the leaf comes out close to 45 kg, do not simply add a third hinge and keep the same model: adding a hinge shares the load but does not increase the capacity of each knuckle. Step up to a thicker leaf or a larger size instead, and use three hinges as well if the door is tall.

Two for a standard 2.1 m interior door. Three for a taller leaf, a solid hardwood leaf, or a leaf with glass in it. Four on a door above roughly 2.4 m, or on a very heavy leaf.

The rule behind it is that the top hinge carries most of the load and the bottom hinge carries the leverage, so a tall door with two hinges puts a bending load on the top knuckle that it was not designed for. If you send us the door schedule with heights and leaf weights, we will mark the hinge count on it.

35 mm and above. Below that there is not enough timber for the screws to hold, and the hinge will pull out of the leaf rather than wear out — a different failure with a different fix.

If your leaf is thinner than 35 mm, tell us the thickness before ordering and we will quote a hinge that suits it. Thin-leaf doors are usually cabinet or lightweight partition doors, and a different product from this range is the right answer.

Yes. Your logo or brand name can be stamped on the leaf alongside the grade and size, and your artwork can be printed on the white box. Both are OEM items quoted with the order.

One thing to plan for: the stamping tool is made per design, so the first order carries a one-off tooling cost that later orders do not. Send the artwork as a vector file if you have one — a photograph of an existing stamp is workable but slower, because we have to redraw it before we can cut the tool.

2,000 pcs per item for a trial order, 20,000 pcs for bulk production. The unit price is tiered by quantity, so the price at 2,000 and the price at 20,000 are not the same number.

2,000 is deliberately low for a hardware item — it is set so a distributor can test a market without committing to a container. If you want to combine several sizes and finishes into one trial order, that is normal: the 2,000 figure applies per item, and we quote the whole basket together.

Two hinges to a white box, each hinge in its own poly bag. The box is plain as standard; your logo and artwork can be printed on it, and a colour box is available as an OEM option.

Cartons are export-packed for sea freight. If your market needs retail-ready packaging — a hanging card, a printed blister, a barcode on the box — say so at enquiry stage, because retail packaging changes the carton dimensions and the freight calculation.

We have our own test data and no third-party certification. There is no EN 1935, no CE mark and no UL listing on this series, and no report from an accredited laboratory.

What we can do is run salt spray to the hours your project specifies, and test load to your method, and send the results. That is factory data, and it is honest data — it is just not the same thing as a notified-body certificate. If your specification calls for a certified hinge, this is the wrong product and we would rather lose the order than have you find out at inspection.

Yes to both, as made-to-order items. 4 inch and 5 inch in 2.5 mm and 3.0 mm are the sizes we hold tooling for and the sizes the market buys; 6 inch and 4.0 mm are produced against a confirmed order.

Above 6 inch is also possible for heavy and security leaves, made to order — we quote from the leaf dimensions, thickness and hole spacing. Production lead time is longer than for stock sizes, so plan the order around it.

30–35 days after order confirmation for standard sizes, longer for made-to-order sizes and for OEM packaging. We ship EXW, FOB or FCA — FOB from Nansha Port, Guangzhou.

Warranty is 3 years on the hinge. Payment terms are confirmed with the quotation, and they depend on whether it is a first order or a repeat. For a first order we will always quote the full specification in writing before you commit, including the grade, the thickness and the finish, because those are the three things that decide whether the price you were quoted is the price of the product you expect.