ISO 1035-1:1980

Overview

ISO 1035-1:1980 - Hot-rolled steel bars - Part 1: Dimensions of round bars specifies the metric preferred and second‑preference sizes, sectional areas and masses per unit length for hot‑rolled steel round bars. The standard provides a tabulated set of diameters and corresponding sectional areas and masses (values are based on a steel density of 7.85 kg/dm³, as stated in the document). Unless otherwise ordered, dimensional tolerances follow the normative tolerances referenced in ISO 1035-4.

Key topics

• Metric preferred and second‑preference sizes for hot‑rolled round bars (diameters listed in the standard’s table).
• Tabulated data showing diameter, sectional area and mass per unit length for each nominal size.
• Tolerances: normal tolerances on dimensions are specified by ISO 1035-4 and apply unless tighter tolerances are requested in the order.
• Basis for mass values: masses in the table are calculated using a steel density of 7.85 kg/dm³ (as noted in the standard).
• Scope boundaries: applies specifically to hot‑rolled metric round bars; it is a technical revision that supersedes earlier IS0 Recommendation R 1035/1-1969.

Sample entries from the ISO 1035‑1 table (illustrative):

• 8 mm - area 0.503 cm² - mass 0.395 kg/m
• 10 mm - area 0.785 cm² - mass 0.617 kg/m
• 20 mm - area 3.14 cm² - mass 2.47 kg/m
• 50 mm - area 19.6 cm² - mass 15.4 kg/m
• 100 mm - area 78.5 cm² - mass 61.7 kg/m
• 200 mm - area 314 cm² - mass 247 kg/m

Applications

ISO 1035‑1 is used by:

• Steel producers and mills for defining and producing standard hot‑rolled round bar sizes.
• Procurement and purchasing teams specifying material sizes and mass for orders and cost estimation.
• Structural and mechanical engineers for material selection, mass calculations and design checks.
• Manufacturers, fabricators and machinists who need standardized diameters and mass per metre for inventory, cutting and process planning.
• BIM/CAD libraries and material databases to ensure consistent sizing and weight data across projects.

Practical benefits include accurate weight estimation, streamlined procurement, clearer specification of tolerances, and improved interchangeability of steel round bars.

Related standards

• ISO 1035-4 - Tolerances of round, square and flat bars (normative reference for dimensional tolerances in ISO 1035‑1).
• ISO 1035 series - other parts cover different product requirements and tolerances for hot‑rolled bars.