Product and application brief
A square nut has a four-sided body and a central internally threaded opening. Its shape is different from a six-sided hex nut. Body width, thickness, corner treatment and mating thread help identify the required product, particularly when a nut must fit a defined recess or surrounding envelope.
Product forms and reference names
| Product form / field | Reference and distinguishing details |
|---|---|
| Regular-height square nut | DIN 557:2026-02 is the current DIN Media record for square nuts, product grade C. The official overview describes M5 to M16 in steel and stainless steel; this is the reference scope, not a confirmed own supply range. |
| Thin square nut | DIN 562:2013-05 is the current DIN Media record for square thin nuts, product grade B. Its overview covers metric threads M1.6 to M10. This is a distinct reference scope, not a confirmed own supply range or a regular-height nut substitute. |
| Inch square nut | ASME B18.2.2-2022 official contents distinguish square nuts, heavy square nuts and square machine screw nuts. Select the intended form and inch thread; do not infer DIN equivalence. |
| Drawing-defined square nut | Unchamfered, single-chamfered and double-chamfered forms are shown by the cited manufacturer. Special width, thickness or corner details require a drawing rather than an assumed catalogue geometry. |
Width, thickness and corner details
Describe the width across opposing flat sides, overall thickness and required chamfer or corner geometry. These are separate from nominal thread diameter. If a nut fits inside another component, provide its mating recess information so that the required envelope is unambiguous. The illustration is a generic structural reference, not a dimensioned design.
Choose the standard and edition explicitly
A purchase description that says only DIN 557 omits the edition. DIN Media lists the 2026-02 edition as replacing 1994-01. For an existing design using an older drawing or reference, retain that reference for review rather than silently assuming the editions or inch-series forms are interchangeable. No official dimension or tolerance table is reproduced here.
Separate square nuts from other constructions
A square exterior alone does not identify every fastening arrangement. Weld features, a surrounding cage or a slot-specific profile must be described as part of their own construction rather than assumed from the words square nut. A plain square nut illustration does not demonstrate welding suitability, locking performance or an installation rating.
Material and finish are specification attributes
Identify the required material designation and finish separately from the shape and thread. Where mechanical properties or inspection documents are required, list those requirements explicitly. A product-grade reference describes its standard context; it is not a declared company certification, stock status or load guarantee.
Specification fields
| Product form / field | Reference and distinguishing details |
|---|---|
| Thread system | Metric diameter and pitch, or inch thread designation and threads per inch; identify any specified fit or thread hand. |
| Body envelope | Width across flats, thickness, corner/chamfer details and any mating recess constraints. |
| Product reference | Regular-height, thin or selected inch form; standard and edition or drawing number and revision. |
| Material / finish | Material designation, coating or surface finish and any separate mechanical or inspection requirement. |
| Quantity / unresolved items | Quantity with unit per line; attach the drawing or specification and mark dimensions or requirements still to be confirmed. |
Common product questions
How is a square nut different from a hex nut?
A square nut has four exterior sides; a hex nut has six. Thread and nominal diameter alone do not establish that their body envelopes or specifications are interchangeable.
Does a thin square nut use the same dimensions as a regular-height one?
Do not assume so. Specify the intended form, body thickness, width and thread. DIN 562:2013-05 identifies square thin nuts, product grade B; DIN 557:2026-02 identifies square nuts, product grade C. Their references do not establish interchangeability.
Does this page confirm DIN or ASME conformity?
No. The references identify product families and published scope only. Exact dimensions, tolerances and any conformity requirements must be established by the selected specification and applicable documentation.
Related nut types
Product references
References checked 6 October 2026 explain product identity. Third-party model names and approvals are not FastenerBridge brand affiliation, stock or certification claims. Final geometry and requirements follow the selected specification.