Sealed Beam and 90 mm Headlamp Modules

Replacing an old sealed beam on a tractor or loader is a dimensional problem before it is an optical one. Two families are involved and the trade numbers are routinely confused.

The three sizes people quote by number

7 in round — 178 mm diameter, SAE type 2D1, trade numbers 6014, 6015, 6016 and the halogen H6014.

"4 × 6" rectangular — SAE writes it as 4 × 6-1/2 in, which is 100 × 165 mm, type 2A1, trade numbers H4656, 4652, H4662.

6052 — 142 × 200 mm, type 2B1. A different family altogether, frequently mislabelled as 4 × 6. SAE J1383 5.3.1 requires the dimensions marked "I" in its figures to be met so that lamps of the same type remain interchangeable; a lamp that misses them will not seat in the original bucket.

90 mm modules

The interface is Hella’s and has become the industry default: 85 × 85 mm hole centres, 14 mm or 16.9 mm holes, 3 mm panel thickness, a Ø90 mm lens in a Ø110 mm module, with 10 mm clearance at the sides and 20 mm above and below for heat. The connector is a Deutsch DT, pin 1 to 56b low beam, pin 2 to 56a high beam, pin 3 to 31 ground. It is a de facto interface, not a DIN or ISO standard — describe it as the 85 × 85 mm pattern rather than as a standard.

Approval: ECE and DOT are not interchangeable

For new type approvals, UN Regulation 149 has replaced R112, R113 and the related road illumination regulations since 14 November 2021; Hella states this in its own module documentation. ECE approval is granted by a third party and marked with an E-mark, with photometry measured in lux on a screen at 25 m. FMVSS 108 works by manufacturer self-certification, marked "DOT" on the lens under S6.5.1, with photometry in candela.

The two beam patterns are shaped differently — ECE enforces a sharp cut-off to limit glare, FMVSS allows more upward light for sign illumination — so one optic cannot satisfy both. A lamp offered with both marks is normally two variants sharing a housing. See our LED tractor headlights for 90 mm modules and sealed beam replacements.