Shower hardware is bought by people who install it themselves — glass shops, aluminium fabricators, enclosure manufacturers. They do not reject samples because the polish is wrong. They reject them because the handle will not bolt to the glass they cut.

The three numbers that must be on the enquiry

1. Glass thickness

Frameless shower doors are normally 8 mm, 10 mm or 12 mm toughened glass. The handle’s stud length and washer stack have to match. A back-to-back handle supplied for 10 mm glass, fitted to 8 mm, leaves the studs proud and the gasket loose; fitted to 12 mm it simply will not engage enough thread. Say the thickness in millimetres in the first message — not “standard”, which means different things in different markets.

2. Hole centres (CTC)

The centre-to-centre distance between fixing holes is the number that decides whether the handle fits the glass that has already been drilled and toughened. Toughened glass cannot be re-drilled — once it is tempered, a new hole means a new panel. If you are replacing handles on an existing enclosure line, the hole centres are fixed and non-negotiable, and a factory that offers “similar” centres is offering you scrap glass.

3. Tube diameter and projection

Diameter drives the grip and the visual weight; projection (how far the handle stands off the glass) drives knuckle clearance and whether the door still clears the return panel when it swings. Both are frequently omitted from enquiries and both are frequently the reason a sample is returned.

A one-line enquiry that gets a usable quote. “Back-to-back D handle, 10 mm toughened glass, 300 mm hole centres, Ø25 mm tube, matt black, 500 pcs, need sample in 2 weeks.” Everything a handle factory needs to price and cut is in that sentence. Compare it with “please quote your shower handles”, which will come back as a catalogue.

Back-to-back, single-sided, or knob

  • Back-to-back (pairs): the standard for a swing shower door — one handle each side, through-bolted. Note that this is normally priced and counted per pair, and that half the quotations you receive will be priced per piece. Confirm the unit before comparing prices; it is the single most common source of a 2× error in this category.
  • Single-sided with a knob on the inside: common on smaller enclosures and wet rooms, cheaper, and requires a different stud arrangement.
  • Towel-bar combination: a handle on the outside and a towel rail on the inside, sharing the same fixings — popular in hotel fit-outs, and heavier, which changes the washer specification.

The parts nobody quotes and everybody needs

A shower handle is not just the tube. The assembly includes studs, the internal sleeve, and — critically — the gaskets or washers that sit between metal and glass. Metal touching toughened glass under load is how panels break, sometimes weeks later. When you ask for a sample, ask specifically for the complete fixing kit as it will be shipped, and check that the washers are present and correctly sized. If the factory ships handles without washers and expects the installer to source them, you need to know that before the first container, not after.

Finish matching is a series problem, not a sample problem

Hinges, clamps, brackets and the handle usually come from different suppliers, and “matt black” from two suppliers is rarely the same black. If you are building enclosures, send the factory a physical sample of the hinge finish you are matching to, and ask for the handle sample to be produced with the same powder batch process you will receive in production. Then ask the more awkward question: what happens to colour consistency between batches six months apart? A factory that polishes and coats in-house can answer this; one that subcontracts finishing must go and ask, which is itself useful information.

Packing, because handles arrive scratched

Polished and satin stainless scratches in transit, and a scratched handle is unsellable even though nothing is functionally wrong. Specify individual poly bags or foam sleeves, a carton count, and whether you need retail-ready boxes with a barcode. For projects, ask for the fixing kit to be bagged with each handle rather than shipped loose in the carton — installers lose loose parts, and the replacement cost is always higher than the packing cost.

A checklist to paste into your enquiry

  • Glass thickness (mm) and whether the glass is already drilled
  • Hole centres (mm), tube diameter (mm), overall length, projection
  • Back-to-back or single-sided; quoted per piece or per pair
  • Material grade per model — 304 for wet areas
  • Finish, with a physical reference sample if matching existing hardware
  • Fixing kit contents, including washers, and whether it is bagged per handle
  • Sample lead time, production lead time, and MOQ in the same unit as the price

How to read the numbers here. Trade figures are CMH’s reading of UN Comtrade import data for the 2025 reporting year, taken from each country’s own reported aggregate lines. Duty rates and certification requirements are quoted from the published tariff and standards documents current in September 2026; classification and duty are decided by the customs authority at the time of entry, not by a supplier or by this page.