Width across flats is the distance between two parallel surfaces on the head of a screw or bolt, or a nut, mostly for torque transmission by positive locking.
spanner (wrench) size and thread diameter of a hex nut
The term width across flats (AF) is used for the following forms:
The width across flats indicates the nominal "size" of the spanner. It is imprinted on the spanners in millimeter (mm) values. Older British and current US spanners (wrenches) have inch sizes that are imprinted in intermediate sizes in fractions.
The two systems are in general not compatible, which can result in rounding of nuts and bolts (i.e. using a 13 mm spanner in place of a 1⁄2 in (12.7 mm)). There are some exceptions with a few sizes being close enough to interchange. This includes 19 mm and 3⁄4 inch (19.05 mm), which are interchangeable for most purposes. Sizes that may interchange, depending on the precision needed, include 2 mm (close to 5⁄64 inch (1.98 mm)), 4 mm (close to 5⁄32 inch (3.97 mm)) and 8 mm (close to 5⁄16 inch (7.94 mm)).
In reality, a wrench with a width across the flats of exactly 15 mm would fit too tightly to use on a bolt with a width across the flats of 15 mm. The tolerances necessary to make the tools usable are listed in documents like ASME/ANSI B18.2.2 for U.S. standards.[1] For instance, a bolt for a 1-inch nominal diameter thread might have flats that are 1.5 inches apart. The wrench for this bolt should have flats that are between 1.508 and 1.520 inches apart to allow for a little extra space between the nut flats and the bolt flats. This means that the wrench slips easily over the bolt, and can be removed easily as well.
Width across flatsedit
Fastener terminology of hex nuts: d: Nominal thread diameter k: Wrench size (width across flats) h: Thickness e: Width across corners
The width across flats of the fastener (for example screws, nuts, clamps) is nominally the same as that on the tool. The table below shows dimensions of metric spanners for selected sizes of metric threads.[2] Note that with ISO 272 1982 the width across flats for M10, M12, M14 and M22 were changed from 17, 19, 22 and 32 mm respectively to the current standard.
Nominal thread diameter (mm)
M2
M4
M5
M6
M8
M10
M12
M16
M20
M24
M30
M36
M42
Width across flats (mm)
4
7
8
10
13
16
18
24
30
36
46
55
65
Widths for bicyclesedit
In addition to industry standards, there are special thread standards, such as the bicycle threads according to DIN 79012, a fastening thread on metric-inch size basis of the designation. Modern bicycle spokes carry the bike thread FG 2.3.[3] A spoke wrench matching the spoke nipple is needed.
^"ASME B18.2.2-2022 Nuts for General Applications: Machine Screw Nuts; and Hex, Square, Hex Flange, and Coupling Nuts (Inch Series)".
^ISO 262:1998 ISO general purpose metric screw threads – Selected sizes for screws, bolts and nuts. International Organization for Standardization. 17 Dec 1998.
wrench, size, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, need, rewritten, comply, with, wikipedia, quality, standards, help, talk, page, contain, su. This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article may need to be rewritten to comply with Wikipedia s quality standards You can help The talk page may contain suggestions July 2020 This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Wrench size news newspapers books scholar JSTOR August 2018 Learn how and when to remove this template message Learn how and when to remove this template message Width across flats is the distance between two parallel surfaces on the head of a screw or bolt or a nut mostly for torque transmission by positive locking spanner wrench size and thread diameter of a hex nutThe term width across flats AF is used for the following forms 2 socket round material with two surfaces 4 socket profile square section 6 socket 8 square regular polygonsContents 1 Spanner 2 Width across flats 3 Widths for bicycles 4 See also 5 ReferencesSpanner editThe width across flats indicates the nominal size of the spanner It is imprinted on the spanners in millimeter mm values Older British and current US spanners wrenches have inch sizes that are imprinted in intermediate sizes in fractions The two systems are in general not compatible which can result in rounding of nuts and bolts i e using a 13 mm spanner in place of a 1 2 in 12 7 mm There are some exceptions with a few sizes being close enough to interchange This includes 19 mm and 3 4 inch 19 05 mm which are interchangeable for most purposes Sizes that may interchange depending on the precision needed include 2 mm close to 5 64 inch 1 98 mm 4 mm close to 5 32 inch 3 97 mm and 8 mm close to 5 16 inch 7 94 mm In reality a wrench with a width across the flats of exactly 15 mm would fit too tightly to use on a bolt with a width across the flats of 15 mm The tolerances necessary to make the tools usable are listed in documents like ASME ANSI B18 2 2 for U S standards 1 For instance a bolt for a 1 inch nominal diameter thread might have flats that are 1 5 inches apart The wrench for this bolt should have flats that are between 1 508 and 1 520 inches apart to allow for a little extra space between the nut flats and the bolt flats This means that the wrench slips easily over the bolt and can be removed easily as well Width across flats edit nbsp Fastener terminology of hex nuts d Nominal thread diameter k Wrench size width across flats h Thickness e Width across corners e 233 k 1 154701 k displaystyle e frac 2 sqrt 3 3 cdot k approx 1 154701 cdot k nbsp The width across flats of the fastener for example screws nuts clamps is nominally the same as that on the tool The table below shows dimensions of metric spanners for selected sizes of metric threads 2 Note that with ISO 272 1982 the width across flats for M10 M12 M14 and M22 were changed from 17 19 22 and 32 mm respectively to the current standard Nominal thread diameter mm M2 M4 M5 M6 M8 M10 M12 M16 M20 M24 M30 M36 M42Width across flats mm 4 7 8 10 13 16 18 24 30 36 46 55 65Widths for bicycles editIn addition to industry standards there are special thread standards such as the bicycle threads according to DIN 79012 a fastening thread on metric inch size basis of the designation Modern bicycle spokes carry the bike thread FG 2 3 3 A spoke wrench matching the spoke nipple is needed See also editISO metric screw threadReferences edit ASME B18 2 2 2022 Nuts for General Applications Machine Screw Nuts and Hex Square Hex Flange and Coupling Nuts Inch Series ISO 262 1998 ISO general purpose metric screw threads Selected sizes for screws bolts and nuts International Organization for Standardization 17 Dec 1998 Ubersicht Gewinde am Fahrrad Retrieved from https en wikipedia org w index php title Wrench size amp oldid 1189195788, wikipedia, wiki, book, books, library,
