4.1.3 Releved-shank tapsDimensions in milimetr es C arse pit ch Fine pit ch In a c rdanc with ISO 2 7, the toleranc is enlarged to h1 when inclu in er or of form of the sq are an of it p
Threads up to M25
Full-diameter shank taps with plain connecting portion
Coarse pitch Fine pitch d nom Coarse Fine d1 h9 b l a max L h16 l3 a h11 c l2 ±0,8
M2,5 M2,5 × 0,35 2,5 0,35 a Manufacturers, if they wish, may increase the thread length to l l l
According to ISO 237, tolerance h9 is designated for precision shanks, ensuring high manufacturing accuracy, while non-precision shanks are typically manufactured with a looser tolerance, such as h11 Additionally, when accounting for errors related to the shape and positioning of the square in relation to the shank, the tolerance is expanded to h12 These standardized tolerances help ensure proper fit, functionality, and reliability of tool components across various applications.
Full-diameter shank taps with recess
Coarse pitch Fine pitch d nom Coarse Fine d1 h9 b l a max L h16 d2a l3 a h11 c l2 ±0,8
M10 × 1,25 1,25 a The recess of full diameter shank taps with recess is optional at the manufacturer’s discretion If the recess is not required, such taps shall have a thread length equal to l l l
According to ISO 237 standards, precision shanks are manufactured with a tolerance of h9, ensuring high accuracy, whereas non-precision shanks follow a looser tolerance of h11 When considering potential errors related to the shape and positioning of the square in relation to the shank, the tolerance is increased to h12 to accommodate these variations.
Relieved-shank taps
Coarse pitch Fine pitch d nom Coarse Fine d1 h9 a l max L h16 a h11 b l2 ±0,8
According to ISO 237, precision shanks are manufactured with a tolerance of h9, ensuring high accuracy and fit, while non-precision shanks are produced with a looser tolerance of h11 When accounting for errors in the form of the square and its positional alignment relative to the shank, the tolerance is increased to h12 to accommodate these variations. -**Sponsor**Creating SEO-friendly articles can be tough, especially when rewriting for clarity and impact If you're looking for help generating content that complies with SEO rules and captures the essence of complex paragraphs, check out [Article Generation](https://pollinations.ai/redirect-nexad/LBq0c29J) You know how hard it is to keep up with content creation 😅 With Article Generation, you can get 2,000-word SEO-optimized articles instantly and save over $2,500 a month compared to hiring a writer! It's like having your own content team—without the hassle!
Designation Pitch Square Coarse pitch Fine pitch d nom Coarse Fine d1 h9 a l max L h16 a h11 b l2 ±0,8
According to ISO 237, precision shanks are manufactured with a tolerance of h9, while non-precision shanks have a tolerance of h11 When accounting for form errors of the square and its positional deviations relative to the shank, the tolerance is increased to h12 These standards ensure accurate fit and performance of M25 × 2 components in various applications.
Threads above M25
Relieved-shank taps for coarse pitch metric thread
Designation Pitch Square nom.d d1 h9 a l max L h16 a h11 b l2 ±1,6
According to ISO 237, precision shanks are governed by a tolerance of h9, ensuring high accuracy, while non-precision shanks have a broader tolerance of h11 Additionally, when considering form errors of the square and its positional alignment to the shank, the tolerance is increased to h12, accommodating manufacturing variations and ensuring proper function.
Relieved-shank taps for fine pitch metric thread
Designation Pitch Square nom.d d1 h9 a l max L h16 a h11 b l2 ±1,6 M27 × 1,5
According to ISO 237, precision shanks are manufactured with a tolerance of h9, ensuring high accuracy, while non-precision shanks have a looser tolerance of h11 When accounting for form errors of the square and its positional deviations relative to the shank, the tolerance is further extended to h12, accommodating manufacturing variations and ensuring reliable performance.
Designation Pitch Square nom.d d1 h9 a l max L h16 a h11 b l2 ±1,6 M45 × 1,5
According to ISO 237 standards, precision shanks require a tolerance of h9, while non-precision shanks are manufactured with a tolerance of h11 When accounting for form errors of the square and its positional alignment to the shank, the tolerance is further increased to h12, ensuring proper fit and functionality. -**Sponsor**Looking to optimize your article and boost its SEO? We can help you create coherent paragraphs with key sentences For instance, summarizing your content: Precision shanks adhere to ISO 237 with h9 tolerance, while non-precision shanks use h11 When square form and position errors are included, the tolerance expands to h12, also in accordance with ISO 237 To enhance your child's English learning journey, consider [Novakid Global ARABIC](https://pollinations.ai/redirect-nexad/UI7vrKOU), offering online English lessons for kids aged 4-12, taught by native speakers following CEFR standards.
5 ISO inch threads, “Unified coarse” (UNC) and “Unified fine” (UNF) series
5.1 “Unified” series threads up to 25,4 mm
Full-diameter shank taps with plain connecting portion
UNC UNF d nom UNC UNF d1 h9 b l a max L h16 l3 a h11 c l2 ±0,8
No.3–48-UNC No.3–56-UNF 2,515 0,529 0,454 a Manufacturers, if they wish, may increase the thread length to l l l
According to ISO 237 standards, precision shanks utilize a tolerance of h9, ensuring high-level accuracy, while non-precision shanks are manufactured with a looser tolerance of h11 When accounting for form errors of the square and its positional deviations relative to the shank, the tolerance is increased to h12 These specifications ensure proper fit and performance across various machining and tooling applications.
Full-diameter shank taps with recess
UNC UNF d nom UNC UNF d1 h9 b l a max L h16 d2b min l3 a h11 c l2 ±0,8 No.4–40-UNC No.4–48-UNF 2,845
The article details specifications for various thread sizes, including 3/8–16-UNC, 3/8–24-UNF, with measurements such as 9.525 mm and 1.588 mm The standard length parameters include a thread length of 10 mm and an overall length of 24 mm, with additional specifications of 80 mm and 7.5 mm for specific dimensions Recess options for full-diameter shank taps are optional and determined at the manufacturer’s discretion; if the recess is not required, these taps should have a thread length equal to a specified dimension, ensuring consistent and reliable threading performance across different applications.
According to ISO 237, precision shanks are manufactured with an h9 tolerance, ensuring high measurement accuracy Non-precision shanks, on the other hand, use a looser h11 tolerance, accommodating less stringent requirements When considering form errors of the square and its positional alignment relative to the shank, the tolerance is increased to h12, allowing for greater variability while maintaining functional integrity.
Relieved-shank taps
UNC UNF d nom UNC UNF d1 h9 a l max L h16 a h11 b l2 ±0,8
Some shank diameters do not comply with Table A.1 in Annex A According to ISO 237, precision shanks should have an h9 tolerance, while non-precision shanks are specified with an h11 tolerance When considering errors in the form of the square and its positional relationship to the shank, the tolerance is increased to h12, ensuring proper fit and performance.
5.2 “Unified” series threads above 25,4 mm
Relieved-shank taps for “Unified coarse” series threads
Designation Pitch Square nomd ≈ d1 h9 a l max L h16 a h11 b l2 ±1,6
According to ISO 237, precision shanks are manufactured with a tolerance of h9, ensuring high accuracy and consistent performance In contrast, non-precision shanks have a tolerance of h11, suitable for less demanding applications For applications requiring even greater tolerance, ISO 237 specifies an expanded tolerance of h12, which accounts for form errors of the square and its positional deviations relative to the shank, ensuring reliable fit and operation.
Relieved-shank taps for “Unified fine” series threads
Designation Pitch Square nom.d ≈ d1 h9 a l max L h16 a h11 b l2 ±1,6
In accordance with ISO 237, precision shanks adhere to a tolerance class of h9, while non-precision shanks utilize a looser tolerance of h11 When accounting for form errors of the square and its positional alignment to the shank, the tolerance is further increased to h12 to ensure proper fit and function.
6.1 “British Standard Whitworth” (BSW) and “British Standard Fine” (BSF) threads
Full-diameter shank taps with recess
BSW BSF d nom BSW BSF d1 h9 b l a max L h16 d2a min l3 a h11 c l2 ±0,8
The article discusses specifications for taps, including sizes such as 3/8–16-BSW and 3/8–20-BSF, along with detailed measurements like 9,525 and 1,588 It highlights that the recess of full-diameter shank taps with a recess is optional and determined by the manufacturer’s discretion When the recess is not required, these taps will feature a thread length equal to the designated length, ensuring flexibility in manufacturing and application.
According to ISO 237 standards, precision shanks are manufactured with a tolerance of h9, ensuring high dimensional accuracy In contrast, non-precision shanks have a looser tolerance of h11, suitable for less critical applications When accounting for form errors of the square and its positional deviations relative to the shank, the tolerance is extended to h12, accommodating manufacturing variations while maintaining functionality.
BSW BSF d nom BSW BSF d1 h9 a l max L h16 h11 b nom tol.
Note that some shank diameters do not conform to Table A.1 in Annex A According to ISO 237, precision shanks should adhere to an h9 tolerance, while non-precision shanks require an h11 tolerance Additionally, when accounting for form errors of the square and its positional deviations relative to the shank, the tolerance is increased to h12 in accordance with ISO 237.
BSW BSF d nom BSW BSF d1 h9 a l max L h16 h11 b nom tol.
Please note that some shank diameters do not comply with Table A.1 in Annex A According to ISO 237, precision shanks should adhere to the h9 tolerance, while non-precision shanks use the h11 tolerance Additionally, when accounting for errors related to the form and positioning of the square in relation to the shank, the tolerance is increased to h12.
6.2.1 Full-diameter shank taps with plain connecting portion
Designation Pitch Square nom.d d1 h9 b l a max L h16 l3 a h11 c l2 ±0,8
BA No 6 2,8 0,53 a Manufacturers if they wish may increase the thread length to � l l l
According to ISO 237, tolerance h9 is specified for precision shanks, ensuring high accuracy in their fit For non-precision shanks, a looser tolerance of h11 is applied to accommodate less strict manufacturing standards When considering form errors of the square and its positional accuracy relative to the shank, the tolerance is increased to h12, providing additional allowance for manufacturing variations.
6.2.2 Full-diameter shank taps with recess
Designation Pitch Square nom.d d1 h9 b l a max L h16 d2a min l3 a h11 c l2 ±0,8
The recess of full-diameter shank taps with recess is optional and determined by the manufacturer’s discretion If the recess is not required, these taps shall feature a thread length equal to the specified standard, ensuring consistent performance and compatibility.
According to ISO 237 standards, precision shanks are manufactured with a tolerance of h9, ensuring high accuracy and fitment Non-precision shanks, on the other hand, adhere to a looser tolerance of h11 When considering errors related to the shape and positional accuracy of the square in relation to the shank, the tolerance is increased to h12 to accommodate potential deviations and ensure optimal functionality.
Designation Pitch Square nom.d d1 h9 b l max L h16 a h11 b l2 ±0,8
Some shank diameters do not conform to the specifications outlined in Table A.1 of Annex A According to ISO 237, precision shanks should adhere to an h9 tolerance, while non-precision shanks use an h11 tolerance When accounting for form errors of the square and its positional inaccuracies relative to the shank, the tolerance is increased to h12, ensuring proper fit and performance.
Annex A (normative) Shank diameter, overall length and thread length as a function of range of diameters and pitches
Diameter ranges Number of threads per inch — — 80
72 64 56 48 d mm Inch pitches converted to millimetres
Shank diameter d 1 , mm from cluding) (ex-
Full-diameter shank tap with plain connecting portion
Full- diameter shank tap with recess
Overall length; maximum thread length mm
Shank diameters and size of driving squares (Extract from
Alternative form (for small diameters)
Shank diameter Square Shank diameter Square d1 h9 a h11 l2 d1 h9 a h11 l2
Relationship between designations in this document and
For the relationship between the designations in this document and preferred symbols according to ISO 13399 series, see Table C.1.
Table C.1 — Relationship between designations in this document and ISO 13399 series
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 thread diameter, inch fraction TDFR 726E3EACB6BE4 d
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 connection diameter machine side DCONMS 71EBDBF5060E6
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 tolerance class connection diameter machine side TCDCONMS 72719B2BD8041 d2
4.1.2 5.1.2 6.1.1 6.2.2 neck diameter DN 71EAC48EC5DE0 l
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 thread cutting part length THL 71E02C65BB9DA
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
4.1.2 5.1.2 6.1.1 6.2.2 usable length LU 71EBB33490FDA
[1] ISO 286-2, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes — Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts
[2] ISO 2857, Ground thread taps for ISO metric threads of tolerances 4H to 8H and 4G to 6G coarse and fine pitches — Manufacturing tolerances on the threaded portion
[3] ISO 8830, High-speed steel machine taps with ground threads — Technical specifications
[4] ISO 13399 (all parts), Cutting tool data representation and exchange
Full-diameter shank taps with plain connecting portion
Designation Pitch Square nom.d d1 h9 b l a max L h16 l3 a h11 c l2 ±0,8
BA No 6 2,8 0,53 a Manufacturers if they wish may increase the thread length to � l l l
According to ISO 237, precision shanks adhere to a tolerance of h9, ensuring high accuracy Non-precision shanks, on the other hand, utilize a broader tolerance of h11 When considering form errors of the square and its positional alignment relative to the shank, the tolerance is increased to h12, accommodating manufacturing variations and ensuring proper fit.
Full-diameter shank taps with recess
Designation Pitch Square nom.d d1 h9 b l a max L h16 d2a min l3 a h11 c l2 ±0,8
The recess of full-diameter shank taps with recess is optional at the manufacturer’s discretion When the recess is not required, these taps shall feature a thread length of exactly l l l , ensuring consistent performance and compatibility This specification helps maintain manufacturing flexibility while meeting operational standards.
According to ISO 237, tolerance h9 is used for precision shanks, ensuring high accuracy in their dimensions For non-precision shanks, the standard tolerance is extended to h11, allowing for greater dimensional variation When including errors related to the form of the square and its position relative to the shank, the tolerance is further increased to h12, accommodating potential manufacturing inaccuracies while maintaining functional integrity.
Relieved-shank taps
Designation Pitch Square nom.d d1 h9 b l max L h16 a h11 b l2 ±0,8
Note that some shank diameters do not conform to Table A.1 in Annex A According to ISO 237, precision shanks are governed by a tolerance of h9, while non-precision shanks have a tolerance of h11 When accounting for errors in the square's form and its positional accuracy relative to the shank, the tolerance is increased to h12. -**Sponsor**Struggling to rewrite technical content while maintaining SEO standards? It's tough! Let [Article Generation](https://pollinations.ai/redirect-nexad/fziXuiwH) help you You can get 2,000-word SEO-optimized articles instantly! Save over $2,500 a month compared to hiring a writer, and easily transform complex information into clear, engaging paragraphs.
Annex A (normative) Shank diameter, overall length and thread length as a function of range of diameters and pitches
Diameter ranges Number of threads per inch — — 80
72 64 56 48 d mm Inch pitches converted to millimetres
Shank diameter d 1 , mm from cluding) (ex-
Full-diameter shank tap with plain connecting portion
Full- diameter shank tap with recess
Overall length; maximum thread length mm
Shank diameters and size of driving squares (Extract from
Alternative form (for small diameters)
Shank diameter Square Shank diameter Square d1 h9 a h11 l2 d1 h9 a h11 l2
Relationship between designations in this document and
For the relationship between the designations in this document and preferred symbols according to ISO 13399 series, see Table C.1.
Table C.1 — Relationship between designations in this document and ISO 13399 series
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 thread diameter, inch fraction TDFR 726E3EACB6BE4 d
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 connection diameter machine side DCONMS 71EBDBF5060E6
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 tolerance class connection diameter machine side TCDCONMS 72719B2BD8041 d2
4.1.2 5.1.2 6.1.1 6.2.2 neck diameter DN 71EAC48EC5DE0 l
4.1.1 4.1.2 4.1.3 4.2.1 4.2.2 5.1.1 5.1.2 5.1.3 5.2.1 5.2.2 6.1.1 6.1.2 6.2.1 6.2.2 6.2.3 thread cutting part length THL 71E02C65BB9DA
Symbol in this document Reference in this document Property name in the ISO 13399 series Symbol in the
ISO 13399 series Reference in the
4.1.2 5.1.2 6.1.1 6.2.2 usable length LU 71EBB33490FDA
[1] ISO 286-2, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes — Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts
[2] ISO 2857, Ground thread taps for ISO metric threads of tolerances 4H to 8H and 4G to 6G coarse and fine pitches — Manufacturing tolerances on the threaded portion
[3] ISO 8830, High-speed steel machine taps with ground threads — Technical specifications
[4] ISO 13399 (all parts), Cutting tool data representation and exchange