Our own factory, plus a partner ecosystem: catalogue sizes for standard parts, your drawing for custom parts.
Conditions first, then standard and material; which documents ship with your batch is written into the order before we quote.
TOOLS
Fastener Specification Charts & Engineering Tools
Reference charts for M6–M36: bolt torque, strength grade and weight — every value shows its formula and basis and can be recalculated. Use the companion torque/weight calculators for combinations outside the charts. Free; estimates for quotation and evaluation.
Companion calculators
For combinations outside the charts — a different K-factor, a different preload ratio, custom sizes.
Bolt Weight Calculator in kg
Unit weight, order total weight and freight estimate for bolts, nuts, washers and threaded rod. Metric & imperial, with per-size weight charts.
Weight · Freight · Imperial
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Bolt Torque Calculator
Tightening torque range and target preload by property class and friction condition (K-factor method), with printable torque chart.
Torque · Preload · K-factor
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Pilot Hole & Drill Size Calculator
Lead hole and clearance hole for a wood screw, in softwood as a measured value and in hardwood as a marked inference, with the closest imperial and metric drills and a printable drilling list.
Hole size · Drill match · Soft / hard wood
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CNC Machining Quote Calculator
Instant cost estimate for CNC-machined parts from drawing parameters: material, feature time, batch curve and post-processing line by line, with cast-blank vs solid-billet route comparison and break-even batch quantity.
Quote · Batch curve · Route compare
Open tool →Reference Charts
One page per size, M6–M36; switch sizes on the page. Same data source as the calculators, free to use.
Multi-chart kit
Download the weight estimation kit (4 full-range charts)
Four full-range weight charts — bolts, anchor bolts, threaded rods, nuts and washers — packed into one zip; enter your email to get it.
Bolt Strength Grade Chart
Mechanical properties of 7 property classes (4.6–12.9 + stainless A2/A4): proof/tensile/hardness and governing standards, sharing torque chart data.
7 classes · ISO 898-1/3506-1 · Selection
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Bolt Torque Chart (Metric & Inch)
All sizes in one table: metric M6–M36 by property class and inch 1/4″–2″ by SAE grade, each size linked to its own page with five friction states; Nm↔ft-lb toggle, printable.
M6–M36 & 1/4″–2″ · Metric + SAE · Printable
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Stud Bolt Torque Chart
Tightening torque for stud bolts at three nut factors (K 0.12/0.15/0.20) × six property classes, target preload included, Nm↔ft-lb toggle.
M6–M36 · K 0.12–0.20 · Printable
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Hex Bolt Weight Chart
Grams per piece and kg per 1,000 pcs across the full length series, incl. matching nut/washer unit weights.
M6–M36 · Per pc / per 1k
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Anchor Bolt Weight Chart
Unit weight for straight / J-hook / L-bend / with-end-plate configurations across full length range, method fully disclosed.
4 configs · M6–M36 · kg↔lb
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Threaded Rod & Stud Bolt Weight Chart
kg/m plus per-piece weights for 100–3000 mm lengths, with pitch, root diameter and tensile stress area; kg/m↔lb/ft toggle.
M6–M36 · kg/m↔lb/ft · Thread data
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Hex Nut Weight Chart
Grams per piece and kg per 1,000 pcs on the ISO 4032 / GB/T 6170-2015 basis, with width across flats and nut height; kg/1000 pcs ↔ lb/100 pcs toggle.
M6–M36 · kg/1k↔lb/100
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Flat & Spring Washer Weight Chart
Flat washers (ISO 7089 / GB/T 97.1-2002) and spring washers (DIN 127) side by side: OD, thickness and unit weight; kg/1000 pcs ↔ lb/100 pcs toggle.
M6–M36 · Flat + spring
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Flange Weight & Dimensions Chart
Weld neck (GB/T 9124.1-2019) + plate slip-on (GB/T 9124.1-2019) on one page: DN15–DN300 OD/bolt holes/thickness/raised face, unit weights in carbon steel/304/316L, PN10/PN16 toggle.
DN15–DN300 · PN10/PN16 · WNF+PLF
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Carriage Bolt Size & Weight Chart
DIN 603 / ISO 8677 / GB/T 12-2013 round head square neck: head/neck/dome dimensions with under-head vs overall length side by side, M6–M20 unit weight per length, g and lb toggle.
M6–M20 · Under-head vs overall · g / lb
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U-Bolt Dimensions Chart
DN15–DN150: inside width, leg length, overall height and matching thread, with a pipe-OD reverse lookup table and per-configuration weight.
DN15–DN150 · Pipe OD lookup · Thread disclosed
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Hex Key Size Chart
Which hex key (Allen wrench) fits a socket head cap screw: ISO 4762 / GB/T 70.1-2008 head and socket width across flats plus ISO 2936 / GB/T 5356-2021 key long and short arm lengths, M3–M24 unit weight by length, g and lb toggle.
M3–M24 · Screw to key · g / lb
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Bolt Wrench Size & Socket Opening Chart
Which wrench or socket fits a hex bolt: width across flats for the bolt, hex nut, flange nut and carriage bolt square neck side by side over M6–M36, with row-level standards and the DIN 933 series difference explained.
M6–M36 · Bolt to opening · Row-level standards
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Drill Bit Size Chart
The drill sizes this site carries in four tables: 169 inch sizes (fractional, number and letter series) and 169 metric sizes, each with its decimal inch and millimetre diameter, the closest drill in the other system, and the basis of the row.
169 + 169 sizes · Inch ↔ metric · Open practice values
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Gasket Size Chart by Flange DN & PN
What gasket fits a DN80 PN16 flange: reverse lookup of inner diameter, outer diameter, thickness and unit weight across the ten sizes in our range in non-metallic flat (GB/T 9126.1-2023) and spiral wound (GB/T 4622.1-2022) gaskets, plus a nominal PN vs Class comparison and a no-interchange warning.
DN15–DN300 · PN10 / PN16 · PN vs Class
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Screw Size Chart (Machine Screws M1.6–M10)
Head diameter dk, head height k and the drive size for metric machine screws M1.6–M10 across five head types (slotted pan ISO 1580 / GB/T 67-2016, cross pan ISO 7045 / GB/T 818-2016, countersunk ISO 7046-1 / GB/T 819.1-2016, cheese ISO 7048 / GB/T 822-2016, socket head ISO 4762 / GB/T 70.1-2008), with a metric to inch comparison and a page for each size.
M1.6–M10 · 5 head types · Drive size
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Bolt Size Chart (Hex Bolts M1.6–M64)
Metric hex head bolt dimensions M1.6–M64: width across flats s, width across corners e, head height k and fillet radius r, in product grade A and grade B, with the thread length b by nominal length for partially threaded bolts (ISO 4017 / 4014, GB/T 5783-2025 / 5782-2025) and the fine pitch options of ISO 8765 / GB/T 5785-2025, plus a page for each size.
M1.6–M64 · s / e / k · Grade A & B
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Spring Washer Size Chart (GB/T 93-2025)
Normal-type spring lock washer dimensions across all 24 sizes of GB/T 93-2025 Table 1 (1.6–48 mm): inner diameter, S(b) and free height with table and page references; the 10 sizes we quote (M3–M24) carry outer diameter and unit weight from the same catalogue coefficients the product pages and the weight calculator use, together with a size-by-size note on how they differ from the 2025 edition.
M3–M24 · GB/T 93-2025 · size-by-size sourcing
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Tap Drill Chart (Metric & Unified Inch)
Tap drill sizes for metric and unified inch thread series: the rule value d − P, the nearest drill in the metric or inch drill set with its percent of thread, and a page for every size that has one. Every figure is computed from one module, and the gaps in each drill set are stated rather than hidden.
Metric & Inch · d − P · Percent of thread
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UNC & UNF Thread Chart (Unified Inch)
Unified inch thread sizes UNC, UNF, UNEF, UN and UNS: threads per inch, pitch in inch and millimetre, basic pitch diameter and basic minor diameter, and the closest metric size, with a page for the most-queried sizes. Nominal diameters and thread counts come from FED-STD-H28/2B; the pitch and the diameters are computed from them.
UNC / UNF / UNEF / UN / UNS · TPI & pitch · Nominal sizes
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US Hex Nut Size Chart (1/4–3 in, UNC-2B)
US (inch) hex nut body dimensions from MS51967D Table I: across flats nominal, maximum and minimum, across corners maximum and minimum, thickness nominal, maximum and minimum, the thread count per inch and the dash numbers for material grades A, B and C. The across-corners column is also recomputed from the across-flats value, and ten common sizes have their own page.
Across flats & corners · Thickness · 1/4–3 in
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US Flat Washer Size Chart (USS & SAE Patterns)
US (inch) flat washer dimensions for the 58 dash numbers 801 to 858: inside diameter ØA, outside diameter ØB, thickness C as basic, maximum and minimum, the ØA and ØB tolerances and the calculated bearing area. The wide and narrow outside-diameter patterns on the same hole are listed side by side, with a page for eight common bolt sizes.
Dash 801–858 · USS & SAE patterns · Bearing area
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US Machine Screw Size Chart (#0–#12 and 1/4–1/2 in)
Machine screws sized the US way: the nominal diameter of every size number from #0 to #12 and of the fractional sizes 1/4 in to 1/2 in, in inch and millimetre, with the UNC and UNF thread counts, the pitch, the closest metric machine screw size and the head and drive names. Diameters and thread counts come from FED-STD-H28/2B; size #14 is outside that source and is not tabulated.
#0–#12 and 1/4–1/2 in · UNC & UNF · Nominal sizes
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Solar Hanger Bolt Size Chart (M8 / M10 / M12, 100–250 mm)
Rooftop solar hanger bolts by size and supply length: nominal machine-thread diameter and coarse pitch, the flange nut's across flats, height and flange diameter, the bonded-washer bore floor, and what is left for the roof build-up. Wood-thread and self-drilling variants, the engagement rules for timber and steel purlins, and the values that are deliberately not tabulated.
M8 / M10 / M12 · Wood thread & self-drilling · 100–250 mm
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Solar Clamp Size Chart (30–45 mm Frame Thickness)
Which end clamp and mid clamp go with a module frame thickness of 30 to 45 mm, one row per band: the grip size, the M8 bolt and the washer and nut that pair with it, and the minimum bolt length floor. The boundary when a clamp is only sold as a range, the material boundary for coastal, industrial and floating jobs, and the values that are deliberately not tabulated.
30–45 mm · End & mid clamp · M8 pairing
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Solar Mounting Hardware: Charts by Part
The solar mounting hardware charts that are live today, part by part: rooftop hanger bolts by size and supply length, and end and mid clamps by module frame thickness. Which part goes to which chart, what decides the size, where a tightening value comes from, and what is deliberately not covered yet.
Hanger bolt & clamps · By part · What decides size
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Spring Pin Size Chart (ISO 8752 / 13337 / 8748 / 8750 / 8751, GB/T 879.1–879.5, Slotted & Coiled)
Dimensions for all five parts of ISO 8752 / 13337 / 8748 / 8750 / 8751 (GB/T 879.1–879.5): every nominal diameter d1 for slotted heavy duty and light duty and for coiled heavy duty, standard duty and light duty, with pre-insertion limit sizes, slot width a, wall thickness s and minimum double shear load. Hole tolerance H12, and H10 for coiled standard duty at d1 ≤ 1.2 mm.
ISO 8752 / 13337 / 8748 / 8750 / 8751 (GB/T 879.1–879.5) · Slotted & coiled · All d1 · shear load
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Cotter Pin Size Chart (ISO 1234 / GB/T 91-2000)
ISO 1234 / GB/T 91-2000 cotter pin (split pin) dimensions: 16 nominal sizes, the hole diameter, with measured pin-body limits, leg-end offset, eye height and width, matching bolt and clevis-pin diameter ranges, 33 nominal lengths and the recommended hole tolerance H13 / H14, plus material, surface treatment and bend-test requirements.
ISO 1234 / GB/T 91-2000 · 16 nominal sizes · Lengths 4–280 mm
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Shackle Size Chart (RR-C-271H)
RR-C-271H w/ Amendment 1 (2022-01-03): Grade A working load limit for the 23 nominal sizes of Type IVA anchor and Type IVB chain shackles, with the standard dimensions and millimetre conversions.
RR-C-271H w/ Amendment 1 · 23 nominal sizes · Grade A / Class 2 / Class 3
Open chart →More tools on the way (chloride corrosion assessment, solar payback period and more).