How locks and padlocks are made in Aligarh and elsewhere
Aligarh district in Uttar Pradesh has "Locks & Hardware" as its One District One Product, and the state ODOP page describes locks, hardware fittings and security products made there. Lock making has several stages: casting or pressing bodies, making levers and pins, cutting keys, plating and assembly. They may be done in one plant or split between workshops, so ask who does what before the first order.
Brass padlock bodies are cast or forged and then machined. Laminated padlocks are stacked from stamped steel plates and riveted. Inside is either a pin-tumbler cylinder or a set of levers. Shackles are bent from steel rod, and better grades are hardened to resist cutting. Keys are cut from brass or steel blanks to a code, and the code decides which lock each key opens.
TradeStat shows India's exports under HS 8301 (locks of base metal) at US$130.5 million in FY2025-26, provisional. Padlocks (830110) were only US$10.0 million of that, and vehicle locks US$78.2 million, so this is a modest export line.
Keying: the check that matters most
A lock is only secure if its key opens it and no other key does. In a small workshop, keys are cut to a limited set of codes, called differs. If the factory uses too few differs, or mixes up keys at packing, one customer's key may open another customer's lock. We check keying three ways.
- Cross-key test. Each sampled key is tried in every other sampled lock of a keyed-different order. Any lock opening with a foreign key is a critical defect.
- Keyed alike and master keyed. For a site set, every lock is checked against the keying chart: change keys open only their own locks, and the master key opens all of them.
- Differs and key count. We ask how many differs were used for the lot, compare it with the claim on the pack, and count keys per lock (often two or three).
What we check on locks and padlocks
| Check | How it is checked | What fails |
|---|---|---|
| Operation | Each sampled lock opened and closed several times with each of its keys; key turns, shackle springs open and latches cleanly | Stiff turn, key sticks, shackle does not spring or latch |
| Keys | Count, cut quality, burrs, bow stamping and code tag against the order | Short key count, sharp burrs, key that needs jiggling |
| Shackle and body | Shackle diameter and clearance measured; hardened-shackle claim checked against the factory's hardness record; body seams and rivets inspected | Thinner shackle than ordered, loose rivets, cracks in castings |
| Door locks | Backset, case size and lever or bolt throw measured; latch and deadbolt operated from both sides; strike plate and screws counted | Wrong backset for the door, bolt short of spec, missing parts |
| Finish | Plating colour against the finish sample, coverage in recesses, coating thickness gauge; salt spray by a lab if ordered | Patchy or thin plating, early rust on steel |
| Claims and labels | Security grade, "hardened", "anti-pick" and pin or lever count on the pack read against the test report and a cut-open sample where agreed | Grade or feature claimed with no report behind it |
Common defects in locks and padlocks
| Defect | Why it matters | Class |
|---|---|---|
| Lock opens with another lock's key | The lock gives no security | Critical |
| Master key does not open all locks in the suite, or a change key opens others | Site security plan fails | Critical |
| Security grade on the pack with no test report for the model | Misleads the end user about the protection bought | Critical |
| Shackle does not latch on closing | Lock looks closed but is open | Critical |
| Stiff mechanism, key sticks | Returns and complaints | Major |
| Fewer keys than ordered | Incomplete product | Major |
| Thin or patchy plating | Rusts outdoors | Major |
| Scratches, polishing marks, stamping slightly off-centre | Appearance only | Minor |
Standards and rules for locks
- EN 12320:2021 covers mechanical padlocks and padlock fittings. It classifies them into six security grades, six corrosion resistance grades and two durability categories, based on machine attack tests plus limited manual attack tests.
- ASTM F883 is the US performance specification for padlocks, with cycle, environmental, forcing and surreptitious entry tests used to grade them.
- EN 12209 covers mechanically operated locks and latches, and EN 1303 lock cylinders. EN 12209 is on the European Commission's list of harmonised standards for construction products, so locks sold for fire or smoke doors need a declaration of performance and CE marking. See CE and UKCA marking.
- ANSI/BHMA A156 series covers US door locks, for example bored and mortise locks, each with its own grade tests.
- California Proposition 65. Brass keys and lock bodies often contain lead, so warnings may be needed. See Prop 65.
All attack and grade tests are laboratory tests. We do not run them. We check that the lab's report names the model shipped and pull and seal samples for a re-test through lab testing coordination when you want one.
Packing, transit and your purchase order
Locks are packed in blister cards or boxes with their keys, and keys are the part that goes missing. We open packs at random to count keys and match key codes to the label. Steel padlocks need dry cartons and desiccant to avoid rust. Cartons are dense and heavy, so carton strength and weight are checked before loading.
Put these in your purchase order:
- Model, body and shackle material, shackle diameter and clearance.
- Mechanism (pins or levers, how many) and the minimum number of differs.
- Keyed different, keyed alike or master keyed, with the keying chart.
- Keys per lock and key material.
- Security grade and standard, with the lab test report for the model.
- Finish, coating thickness and any salt-spray requirement.
- Pack artwork, barcodes, warnings and carton weight limit.
Book an inspection in Aligarh or anywhere in India.
Sources
- ODOP Uttar Pradesh: Aligarh district, Locks & Hardware
- Department of Commerce, TradeStat: commodity-wise exports (HS 8301; FY2025-26 provisional)
- EVS: EN 12320, Building hardware: Padlocks and padlock fittings (2012 edition withdrawn, replaced by EN 12320:2021)
- ASTM F883, Standard Performance Specification for Padlocks
- European Commission: harmonised standards for construction products (summary list)