Wire stock

Wire stock is feed material for drawing, forming, winding, cutting or other manufacturing operations. A useful purchase description identifies both the material and the delivery state: cross-section, dimensions, alloy, condition, surface and package. A diameter or a familiar alloy name cannot establish that a coil will run in a particular machine or produce an acceptable finished part. Treat electrical, spring and medical wire as application-specific products with their own requirements, rather than interchangeable examples of a single commodity.

Dimensions: specify the actual cross-section

In Alleima's 7C27 metric tolerance table, 1.00 mm nominal wire falls in the over 0.50 through 1.00 mm band. Its normal D3 tolerance is ±0.005 mm, giving 0.995–1.005 mm. Specify the ordered tolerance grade and confirm the spool dimensions match the feed equipment. Alleima 7C27 diameter tolerances

For round wire, record nominal diameter, units, permitted deviation and any out-of-roundness requirement. For flat or profiled wire, identify thickness, width, corner geometry and the drawing revision. Do not convert a round-wire order into a rectangular-wire order merely by preserving cross-sectional area: the resulting part geometry and tooling interface differ.

Gauge numbers need a named system. MWS defines American Wire Gauge (AWG) from 4/0 at exactly 0.4600 inch and AWG 36 at exactly 0.0050 inch, with intermediate sizes related geometrically. A larger AWG number represents a smaller nominal conductor diameter. State the actual diameter alongside the gauge; an unqualified “20 gauge” is an incomplete procurement instruction. MWS, Medical FAQs

For insulated wire, distinguish bare conductor diameter from overall diameter. MWS defines insulation build as overall insulated diameter minus bare-wire diameter. For an ideal concentric round coating, radial thickness is half that difference. This matters when checking a guide bore or available winding space: conductor area and the space occupied by the insulated wire are different quantities. The insulation material and build also need identification. MWS, Medical FAQs

MWS's magnet-wire tool explicitly uses NEMA MW 1000-2015 for listed insulation builds and internal standards for values outside that coverage. Its resistance tables state a reference temperature of 20°C. Preserve those qualifications when transferring a catalog value; neither a gauge designation nor a room-temperature resistance value establishes current capacity or an application's allowable operating temperature. MWS, Magnet Wire

Material condition and surface are separate requirements

Drawing can change mechanical properties as it reduces diameter. Gibbs describes annealing between drawing stages to restore ductility, followed by further drawing to reach the required size and strength. Its guide also distinguishes drawing soaps and metallic nickel coatings used to assist processing. Thus “bright,” “soap coated,” “annealed” and “spring temper” describe different aspects of the supplied product; they should not be substituted for one another. Gibbs, A Layman's General Guide to Stainless Wire

A spring-wire tensile range can depend on diameter. Gibbs's Type 302 sheet lists 275–304 ksi for diameters over 0.037 through 0.041 inch, compared with 175–205 ksi over 0.225 through 0.250 inch. It warns that straightened-and-cut wire can have tensile strength reduced by 10% from its table. These are supplier reference data, explicitly disclaimed as engineering/design values; use the ordered specification and inspection results for acceptance. Do not apply either range to all Type 302 forms or infer spring fatigue life from tensile strength alone. Gibbs, Type 302 Stainless Steel Wire technical sheet

A different product illustrates why “stainless wire” is insufficient: Alleima 7C27 medical wire is supplied soft, with a stated supplied tensile range of 730–900 MPa. Its anti-corrosion oil should remain during storage; after removal, the unhardened wire should not be stored in high humidity. These instructions belong to that product, not every stainless alloy. Determine cleaning and downstream processing from the selected wire's documentation. Alleima 7C27 medical wire, updated 27 May 2025

Package and feeding compatibility

A spool is a machine interface as well as packaging. Alleima's processing page lists flange, barrel, bore and traverse dimensions across several spool families. For example, its DIN 200 entry has a 200 mm flange, 125 mm barrel, 36 mm bore, 200 mm overall length and 160 mm traverse, with a listed normal net weight of 10 kg. Those dimensions and listed wire range are one manufacturer's offering, not a universal promise attached to any “10 kg spool.” Alleima, Wire processing

Before ordering, agree how the package fits the payoff and how the wire reaches the first tool. Record the permitted package mass and handling method, winding direction where relevant, continuous-length expectations, and whether joints are allowed. Where free-coil shape affects feeding, agree a cast/helix measurement method and acceptance limits with the supplier instead of borrowing welding-wire limits for unrelated stock. A trial package is useful when the machine's feed behavior has not been demonstrated.

For straight lengths, specify cut length tolerance, straightness, end condition and acceptable surface marks. For coils, identify inside diameter and packaging requirements rather than assuming that equal net mass means equal coil geometry. Retain package identity when transferring material to another reel; a replacement reel label should still connect the material to its source lot.

Bounded dimensional example

Original calculation using the 7C27 metric tolerance table: a 1.00 mm nominal diameter falls in its over-0.50-through-1.00 mm row. The normal D3 tolerance is ±0.005 mm, giving 0.995–1.005 mm. D1 and D2 are alternative supplier tolerance grades, not synonyms for D3. Alleima 7C27, tolerance table, 27 May 2025

Using round-section area A = πd²/4, nominal area is 0.78540 mm²; the diameter endpoints give 0.77756 and 0.79327 mm², approximately −1.00% and +1.00%. A 100 m length therefore occupies approximately 78.54 cm³ at nominal size. These are geometric calculations, excluding coating, end losses and dimensional variation along the length. They do not establish usable part count: include setup consumption, cropped ends and process scrap separately.

Procurement and receiving record

Use a structured record that a person or an agent can compare against the quotation:

Source scope

The cited Gibbs PDFs do not display a technical revision date; a date in the Type 302 upload path is not an edition statement. The Alleima 7C27 PDF prints its 27 May 2025 update on each page. The MWS and Alleima processing pages are undated technical web references reviewed for this draft. The MWS tool's cited 2015 standard basis is retained as published, without asserting it is the latest standard edition.

Related reference

Stock forms and dimensions