What is the smallest quantity you will actually quote?

There is no floor we turn away at. What changes at low quantity is the price structure — setup is a larger share of the piece price, so fifty pieces will not carry a volume price, and we will say so plainly rather than quoting a number that only works at ten thousand. If the piece price at your quantity is uncomfortable, tell us, and we will look at whether a slightly larger run with staged shipment is cheaper overall.

Can you make the replacement stronger than the original so it lasts longer?

Sometimes, and it is worth asking — but carefully. If the original failed by relaxation, a modest change in material or a preset can genuinely improve service life at no cost penalty. But a stronger spring changes the closing force, which for door hardware is a certification and usability characteristic, not just a number. We would rather discuss the change with you than deliver a part that quietly behaves differently from the one it replaces.

We have twenty different legacy springs, not one. Is that a problem?

That is the case this service exists for. Send them all at once with whatever documentation exists — reviewing twenty together is much more efficient than twenty separate inquiries, and it usually turns out that several can be consolidated onto fewer designs, which reduces both your inventory and your unit cost.

Small-Batch and Replacement Door Springs: When the Original Is Gone

Most spring articles are written for a new product going into production. This one is for the opposite situation: the product already exists, it is installed in buildings, and the spring that keeps it working is no longer available. That is a routine job, not an awkward exception — but it is sourced differently, and the difference is worth understanding before you start calling factories.

The four situations this covers

A discontinued model with an installed base. The closer or hinge is out of production, but thousands are hanging in buildings and the service business still needs spares. Annual quantities are small and indefinite.
The original supplier is gone or has moved on. Closed, acquired, relocated to a region you are exiting, or simply no longer interested in a low-volume legacy part.
A new design in the validation stage. You need dozens or a few hundred pieces to build prototypes and run a cycle test before committing to tooling and volume (see our prototyping without hard tooling guide).
A long tail of SKUs. A distributor or hardware brand carrying many models, each moving small volumes — where the sourcing problem is not any single part but the overhead of managing dozens of small orders.

Why factories say no, and why we do not

Low quantity is not really about the machine. A CNC coiler will run fifty pieces perfectly well. What a factory is actually declining is the fixed cost around the run: setup, first-article measurement, paperwork, a certificate, packing, and a slot in a schedule built around volume orders. On a fifty-piece order the setup dominates the price, and on a factory's cost model that looks like a job not worth taking.

Our position is different because we are not selling the machine time. We aggregate that overhead across many small jobs, we know which of our qualified plants is set up for the wire size and process your part needs, and we can place a short run without disrupting a volume schedule. That is what no minimum order quantity actually means in practice — not that fifty pieces cost the same per piece as fifty thousand, but that fifty pieces is a job we will quote, run, and stand behind (see working with a manufacturing integrator).

When all you have is a sample

For legacy door hardware this is the normal starting point. Our reverse-engineering guide covers the general method — what measures directly (geometry, rate, alloy family) and what has to be inferred (exact grade, original tolerances, secondary processes). Three cautions are specific to door springs:

A used spring has already relaxed. Pull a spring out of a closer that has been on a door for fifteen years and its free length and force are lower than the day it was made. Copy it exactly and you have specified a worn part — the replacements will be weak from day one. New-old-stock samples avoid this entirely. If you only have used ones, tell us how long they were in service and in what environment, and we compensate deliberately rather than silently.
Handing cannot be assumed from one sample. If the part is a handed torsion spring, one sample tells us the hand of that sample, not which hands you need or in what ratio. Send one of each if you have them, and tell us the door configuration (see our self-closing hinge guide).
Send more than one, and say which is which. Five to ten pieces reveal the production window rather than one part's values. If some are unused and some are ex-service, label them separately — the difference between the two is itself useful data about relaxation in service.

What to send us

A quote does not need everything. It needs enough to avoid guessing:

The samples, ideally several, labelled new versus used
Which product they came from — model, and whether it is a closer, hinge, exit device, or lock
The quantity you need now, and the rough annual quantity if this becomes a repeat item
The environment: interior, exterior, floor-recessed, coastal
Any drawing, even an old, incomplete, or superseded one — a bad drawing is better than none
Whether the part is handed, and if so how many of each hand

Our door spring drawing checklist lists the same information in drawing form, and our RFQ guide covers the general case.

What comes back

You get a formal drawing derived from the samples for your approval, then samples against that drawing, then production. The drawing becomes yours — which closes the documentation gap that created the problem in the first place, and means the next reorder is a part number rather than another archaeology exercise (see our drawing requirements guide).

Lead times for short runs are usually driven by material availability rather than machine time; see our sample and production lead times guide for realistic planning.

Send samples or a description through our RFQ form — and see our architectural hardware overview for the wider category, or our door closer springs article for why the replacement often fails the same way the original did.