Cast Iron Flat Bar Weight Calculator
Calculate the weight of Cast Iron Flat Bar by entering your dimensions. The density of Cast Iron is 0.26 lb/in³ (7197 kg/m³). Use this calculator for quick stock weight estimates in your CNC machining projects. Accurate weight calculations are essential for shipping quotes, material cost estimation, fixturing load analysis, and structural design verification. The theoretical weight formula assumes a uniform cross-section and standard alloy density; actual weights may differ slightly by grade and mill tolerance. Weight data is calculated using the standard volumetric formula multiplied by the material density constant shown above.
Material Properties
| Material | Cast Iron |
| Shape | Flat Bar |
| Density | 0.26 lb/in³ / 449.3 lb/ft³ / 7197 kg/m³ |
| Example Weight | 1.56 lb / 0.708 kg |
Compare Materials — Flat Bar
| Material | Weight (lb) | Weight (kg) |
|---|---|---|
| Aluminum | 0.585 | 0.265 |
| Titanium | 0.966 | 0.438 |
| Cast Iron (current) | 1.56 | 0.708 |
| Steel | 1.7 | 0.771 |
| Stainless Steel | 1.725 | 0.782 |
| Brass | 1.839 | 0.834 |
| Copper | 1.944 | 0.882 |
Sourcing and Use Notes
Cast iron stock comes in three families with very different mechanical behavior. Gray iron (ASTM A48 Class 25–40) has graphite flakes that damp vibration — preferred for machine bases, engine blocks, and gear housings, with machinability index around 1.6× faster than mild steel. Ductile iron (ASTM A536, often called nodular) substitutes spheroidal graphite for flakes and is twice as tough as gray iron, used for crankshafts and pressure pipe. Malleable iron is annealed white iron and behaves between the two. All cast irons produce abrasive silica dust during machining — use vacuum collection and respirators.
Rectangular flat bar is the go-to stock for brackets, fabricated frames, machine slides, gibs, knife edges, and electrical bus bars. Standard hot-rolled flat bar holds about ±1.5% on cross-section per ASTM A6 — fine for weldments but loose for machine-fit features, so over-size for finishing operations. Cold-finished flat bar (1018 or 12L14 in steel; 6061-T6511 in aluminum) holds tighter tolerances and presents a clean machinable surface. Edges are roll-formed with a small radius; specify '90-degree cut edge' if a sharp corner is critical.
Common Applications
Cast Iron Flat Bar is a standard stock form used in structural frames, machine bases, brackets, and fabricated components. Its consistent cross-section simplifies weight-per-foot calculations and material takeoffs for procurement and shipping cost estimates. Engineers and machinists rely on theoretical weight data during the quoting and planning stages before final parts are produced. For large orders or weight-critical designs, request certified mill test reports (MTRs) to confirm actual density and alloy composition.
Sourcing and Weight Tolerance Note
This weight is based on the theoretical density of Cast Iron. Mill tolerances (ASTM A6 allows ±2.5% on cross-sectional area for structural shapes) and surface treatments (anodizing, plating, painting) may add 1–3% to actual shipped weight. Order 5–10% material overage to account for saw kerfs and offcuts. Always verify actual material density with your supplier's material test report (MTR) for critical structural or load-bearing applications. Compare weights across materials using the comparison table above to make informed material selection decisions for your project.