TopThread™ Insert Overview style chip thread tolerance control — K neutral positive profile standard class cresting application page(s) General use for 60° thread forms, NT-K NT NTP Partial Profile 60° – – N such as ISO and UN, wherenon-cresting inserts are desired toF13–F15 cut a variety of pitches. Coarse pitch 60° thread forms, such NT-CK Partial Profile 60°— coarse pitch– – N as ISO and UN, where non-crestinginserts are desired to cut a varietyF15 of pitches. Fine pitch 60° thread forms, such NTF NTK Partial Profile 60°— fine pitch– as ISO and UN, where non-cresting–Ninserts are desired to cut a varietyF16of pitches — able to thread close to shoulders. NTC American UN ANSIB1.1:74 2A/2B Y Widely used inch-based 60° V-formfor all industries.F17 Controlled root radius on external NJP UNJ SAEA588791 3A/3B N threads for military and aerospace F18 industries. Controlled root radius on external NJK UNJ —fine pitch SAEA588790 3A/3B N threads for military and aerospaceindustries — able to thread closeF18 to shoulders. NDC-V NPT ANSI/ACMEB1.201:1983StandardNPTY National Pipe Thread standard formsfor pipe fittings.F18 NDC-V-M NPT —multi-tooth ANSI/ACMEB1.201:1983StandardNPTY High-productivity multi-tooth threadinginserts for NPT threads.F19 BS 84:1956, NWC-E Whitworth,BSW, BSP ISO 228/1: Medium1982,Class AY Widely used 55° form for gas andwater connections.F19 DIN 259 60° V-form with large radius for casing, NDC-RD API Round API STD. Standard5B:1979API RDYtubing, and line pipe in the oil andgas industry, including 8 andF20 10 round forms. 29° truncated thread form for motion NA Acme ANSIB1.5:19883G N applications in a wide variety F21 of industries. NAS Stub Acme ANSIB1.8:19882G Shallow depth 29° truncated threadNform for motion applications in a wideF22variety of industries. NTB-B American Buttress— 45° clearanceANSIB1.9:1973Class 2flank leading (Pull)Sawtooth form for axial load bearingNapplications in a variety of industries —use the “B” style when the 45°F22clearance flank is the leading flank. F8 widia.com