Door Hinge (steel, pair)

Material Composition Assumptions

A standard steel door hinge pair contains approximately 400 grams of total material. Carbon steel comprises roughly 380 grams or 95% of the total weight, providing the structural strength and durability required for repeated use cycles. Minor alloying elements including chromium and molybdenum represent about 15 grams or 4% of the composition, enhancing corrosion resistance and mechanical properties. Surface finish coatings such as zinc plating or protective paint account for the remaining 5 grams or 1% of the total mass, extending product lifespan in various environmental conditions.

Manufacturing Geography

China serves as the primary manufacturing region for steel door hinges due to its dominant position in global steel production and established hardware manufacturing infrastructure. The Chinese electrical grid operates at an average carbon intensity of 555 grams of CO2 per kilowatt-hour, reflecting the continued reliance on coal-fired power generation for industrial processes. This grid intensity directly impacts the carbon footprint of steel production facilities and downstream manufacturing operations including hinge forming, machining, and surface treatment processes.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
China	555 gCO2/kWh	52	Baseline
United States	386 gCO2/kWh	44	-15%
Germany	366 gCO2/kWh	42	-19%
India	708 gCO2/kWh	61	+17%
South Korea	436 gCO2/kWh	47	-10%

Provenance Override Guidance

1. Steel production method documentation specifying electric arc furnace versus blast furnace processing with actual energy consumption data
2. Recycled content certification showing percentage of post-consumer or post-industrial steel feedstock used in manufacturing
3. Manufacturing facility energy audit results including electricity consumption per unit and renewable energy sourcing agreements
4. Transportation manifest detailing shipping distances and modal splits from steel mill through final assembly and distribution
5. Surface treatment process specifications with actual chemical consumption and energy requirements for plating or coating operations

Methodology Notes

• The CCI score represents cradle-to-gate emissions including raw material extraction, steel production, hinge manufacturing, and delivery to distribution centers
• Scope 3 emissions dominate the footprint due to energy-intensive steel production processes occurring upstream in the supply chain
• The functional unit assumes a standard residential door hinge pair suitable for interior applications with moderate duty cycles
• End-of-life disposal and recycling impacts are excluded from the primary score but could provide carbon credits in extended assessments
• Data gaps exist around regional variation in steel production efficiency and the specific energy requirements for precision machining operations