Restoration & Metalwork Engineering Specification Guides

Reference notes from our specification desk covering historic duct boot sizing, convective free-area airflow inside wood radiator enclosures, and NEC electrical cutout tolerances for solid C260 brass, #4 brushed 304 stainless, and architectural steel. Every dimension table links directly into our 1:1 CAD configurator.

1/8-inch solid unlacquered C260 brass square lattice floor register installed in quarter-sawn white oak flooring

Vent Grilles & Return Air · 6 min specification note · Presets from $225

Replacing Odd-Size & Gravity-Furnace Vent Covers in Pre-1950 Homes

Houses built before 1950 rarely use modern 4" × 10" or 6" × 12" stamped sheet-metal boots. Tinsmiths hand-braked galvanized risers to fit actual joist bays, plaster stud cavities, and deep window stools. Below are live free-airflow calculations, walk-on plate deflection rules, and exact CAD sizing for common historic rough openings.

Plate Thickness: 1/8" (0.125") walk-on solid sheet
Duct Envelope: 2-1/4" × 2-1/4" up to 36" × 24"
Sizing Increment: 1/16" (0.0625") · ±0.005" kerf
Turnaround: 4–8 business days · Free US shipping

Read Specification Guide Load 7-3/8" × 13-1/4" in CAD

Satin solid brass Regency cane radiator grille panel inset inside painted historic window-seat millwork

Radiator Panels & Millwork · 6 min specification note · Presets from $545

Radiator Cover Grille Sizing: Free-Area Airflow, Steam Heat Output & Solid Brass vs. Perforated Sheet

A wood radiator enclosure works as a convective chimney: cool floor-level air enters under the bottom rail, sweeps upward across cast-iron fins, and discharges into the room through the front grille. Choosing hardware-store perforated aluminum with 30% open area traps heat inside the cabinet, warps solid wood tops, and cuts room BTU delivery. Here is how to size rabbet clearances and open free area properly.

Sheet Gauge: 16ga (0.063") solid brass, stainless & steel
Single-Sheet Max: Up to 44" × 30" (1/16" increments)
Active Free Area: 54%–67% open across window
Rabbet Clearance: Order 1/8" under pocket W × H

Read Specification Guide Load 20" × 18" in CAD

Custom-cut brushed solid brass kitchen range backsplash with laser-cut duplex outlet opening behind a gas range

Kitchen Range Backsplashes · 7 min specification note · Presets from $365

Specifying a Custom-Cut Solid Brass or 304 Stainless Range Backsplash (30", 36", 44" & Outlet Cutouts)

Historic plaster walls, inset face-frame cabinets, and tiled alcoves rarely measure a true 30.00" or 36.00" behind a range, and field-cutting electrical boxes into heavy sheet metal kinks the face. This specification covers three-point width measurement, NEC single-gang and two-gang wallplate tolerances, high-temperature adhesive mounting, and C260 brass vs. 304 stainless performance.

Sheet Gauge: 16ga (0.063") solid flat sheet
Sheet Envelope: 12" × 8" up to 44" × 30"
Outlet Cutouts: 1-gang & 2-gang NEC · +$25 each
Alloys: C260 Solid Brass & #4 304 Stainless

Read Specification Guide Load 29-3/4" × 18" in CAD

Working from a multi-room historic duct or millwork schedule?

All parts are CAD-drawn to 1/16" (0.0625") increments and fiber-laser cut in the United States from heavy flat solid sheet, shipping in 4–8 business days with free US parcel delivery.

How to Measure Open Live 1/16" CAD