Hex Bar 6061-T6

Hex Bar 6061-T6 or round starting stock?

For a part that retains a regular 20 mm AF hexagon, compare the ideal starting sections before choosing a machining route. The smallest circle enclosing that hexagon touches its six corners; its diameter equals the hexagon's AC, not its AF.

Hex stock has about 17.3% less theoretical starting mass than the minimum enclosing round stock in this example. This assumes equal lengths, equal nominal density of 2,700 kg/m³, ideal sharp corners and zero machining allowance. It is not a price or machining-cost saving. Actual stock sizes, tolerances, surface cleanup, corner condition and quotations determine the purchasing choice; use unrounded geometry for the comparison.

For AF = 20 mm: Hex area = √3 / 2 × AF² Enclosing round diameter = 2 × AF / √3 Round area = π × AF² / 3 Relative mass reduction = (1 − hex area / round area) × 100 ≈ 17.3%

Check machining allowance using dimensional limits

Plan Hex Bar 6061-T6 stock around the smallest permitted AF and the largest finished diameter. This hypothetical example turns a centred 19 mm cylinder from nominal 20 mm AF stock; the stated tolerances are example inputs, not supplied-product limits.

1. 01

   Find the minimum stock AF

   Example stock is 20.00 ± 0.10 mm AF. Its lower size limit is 20.00 − 0.10 = 19.90 mm; do not use nominal size as the guaranteed minimum.

2. 02

   Find the maximum finished diameter

   Example finished diameter is 19.00 ± 0.05 mm. Its upper size limit is 19.00 + 0.05 = 19.05 mm; this is the diameter the blank must accommodate.

3. 03

   Calculate the nominal single-side margin

   For concentric ideal sections, (19.90 − 19.05) ÷ 2 = 0.425 mm per side at the flats. A large corner-to-corner dimension does not increase this minimum margin.

4. 04

   Check the full machining setup

   Assess surface cleanup, straightness, local defects and setup eccentricity against the drawing. A positive geometric margin alone does not prove that every blank will yield a conforming part.

This example establishes geometric allowance only. Confirm actual stock limits, corner and surface condition, the machining sequence and inspection requirements before selecting a production blank.

From hex bar to a threaded connector

A hypothetical connector made from Hex Bar 6061-T6 retains a central hexagonal section for wrench access while both ends are turned and threaded. The example connects stock selection to a possible process; thread sizes, part dimensions and acceptance limits come from the finished drawing.

1. 01

   Cut a suitable blank

   Choose AF from the retained hex requirement and the turned features. Specify blank length with the facing and workholding allowance needed by the selected process.

2. 02

   Turn the ends and retain the hex

   Machine the cylindrical features while preserving the intended wrench section. If the original flats meet the finished AF and surface requirements, separate milling of those flats may be unnecessary.

3. 03

   Machine the specified threads

   Produce the end threads defined by the drawing. Confirm thread length, reliefs, concentricity and inspection requirements rather than selecting a thread solely from nominal stock AF.

4. 04

   Deburr and inspect

   Check the retained AF, turned diameters, threads and end condition against the drawing. Agree surface protection and any subsequent finishing as part of the complete requirement.

The retained flats must satisfy the finished part's dimensional and surface requirements to avoid additional machining. This example does not establish a thread load rating or an APW machining-service commitment.