The dimensional data behind our size charts, as clean CSV and JSON. 872 records across 16 DIN, ISO and ASME standards, free for commercial use with attribution.
The same files are available from GitHub. We version the dataset: this page describes v1.0.0, published 2026-10-24T05:29:54Z.
| Standard | System | Component | Records |
|---|---|---|---|
| DIN 931 | Metric | bolt | 119 |
| DIN 933 | Metric | bolt | 154 |
| ISO 4014 | Metric | bolt | 119 |
| ISO 4017 | Metric | bolt | 154 |
| DIN 934 | Metric | nut | 44 |
| ISO 4032 | Metric | nut | 44 |
| DIN 125-A | Metric | washer | 30 |
| ISO 7089 | Metric | washer | 30 |
| DIN 127-A | Metric | spring washer | 54 |
| DIN 7980 | Metric | spring washer | 32 |
| ASME B18.2.1 | Imperial | bolt | 22 |
| ASME B18.2.2 | Imperial | nut | 22 |
| ASME B18.3 | Imperial | screw | 18 |
| ASME B18.21.1 | Imperial | spring washer | 18 |
| DIN 912 | Metric | screw | 6 |
| ISO 4762 | Metric | screw | 6 |
Fields: standard, size, system, grade, finish, component and nominal dimensions in millimetres. Mechanical properties are included for bolts and screws where the standard defines them; weight is included where the upstream table publishes it.
| Field | Type | Notes |
|---|---|---|
standard | string | e.g. DIN 931 |
size | string | Metric M6 or imperial 1/4, 1-1/8 |
system | string | Metric or Imperial |
grade | string | Property class (8.8) or material grade (A4-70), as catalogued |
finish | string | Plain, Stainless Steel, Zinc Clear, as catalogued |
component | string | bolt, nut, screw, spring washer, washer |
width_across_flats_mm | number or null | Width across flats in mm; socket key size for DIN 912 / ISO 4762 |
head_height_mm | number or null | Head height k (bolts/screws) or nut height m (nuts), mm |
inner_dia_mm | number or null | Washer bore d1, mm |
outer_dia_mm | number or null | Washer outside diameter d2, mm |
thickness_mm | number or null | Washer thickness h / s, mm |
tensile_mpa | number or null | Tensile strength of the property class, MPa |
yield_mpa | number or null | Yield or 0.2 percent proof stress, MPa |
weight_per_1000_kg | number or null | Nominal mass per 1,000 pieces (DIN 7980 only) |
source | string | Public reference table the record was catalogued from |
inner_dia_mm is null on a bolt because a bolt has no bore - not a 0 mm bore.width_across_flats_mm is null on a washer because a washer has no hex.tensile_mpa is null on nuts and washers because their standards do not define a tensile strength for the part (nut property classes define proof load stress).If you filter on inner_dia_mm > 0 you will silently drop every bolt. Filter on component instead.
Nominal values only. Each standard defines its own tolerances; tolerances are not included in this release. This is a convenience dataset, not a normative document: for design, certification or acceptance testing, use the standard text itself.
The (standard, size) pairs were cross-checked against the corresponding published size charts: nominal values fall inside the chart tolerance ranges. Known limitations, including the fields withheld for a few imperial standards and the finish selected per grade, are documented in the README in the repository.
A machine-readable citation is in CITATION.cff. Correction requests and issue reports are welcome through the repository issue tracker.
Data: CC BY 4.0 - use it freely, including commercially, with attribution. Attribution example: Fastener standards data from Longze Engineering (https://lz-engineering.com).