2-14 F-PTF F-PTF (Dryseal fine) External Thread Specifications

2-14 F-PTF

ASMESTD: ASME B1.20.3SOURCE: Table C1 · p. 18TYPE: External (bolt/screw)CLASS: —SERIES: F-PTF (Dryseal fine)TAPER 1:16
Major diameter
2.3745 – 2.3622
max – min, at the gage plane
Pitch diameter
2.31784 – 2.30892
max – min, at the gage plane
Minor diameter
2.2682 – 2.2557
max – min, at the gage plane
Pitch
0.07143
14 threads per inch

Thread profile

gage plane: hand-tight, L1 from small endthread axisD1 = 2.3745–2.3622major dia (crest)E1 = 2.31784–2.30892pitch dia, basic 2.31338K1 = 2.2682–2.2557minor dia (root)P = 0.0714360°⟂ axis30°crest flat = 0.0030–0.0050crest truncation 0.0026–0.0043root flat = 0.0050–0.0070root truncation 0.0043–0.0061H0.061859h0.054959 max0.051459 mintaper 1:16 on dia (1:32 on radius) · β = 1° 47′ 24″, included 2β = 3° 34′ 47″ · bisector ⟂ axisexternal thread (male)

External profile over three pitches at the gage plane, drawn at maximum material (sharpest crest, flattest root); hatched bands are the truncation zones. Diameters shortened.

Thread length, taper and gage planes

plane 0 · E02.28794D0 2.3429 · K0 2.2365plane 1 · E12.31338D1 2.3683 · K1 2.2619plane 2 · E22.32675D2 2.3817 · K2 2.2753pipe OD D 2.3750fitting OD D2 2.387MALE · 2-14 F-PTFtrue scale (lengths and diameters); axis below, not drawnL1 0.4070 (5.70 thd)full thread 0.6210 (8.69 thd)V 0.1429shoulder 0.8714

Lengths, taper and gage planes to scale; diameters shortened. D and K at the planes are calculated with the mean truncations.

Limits of size, class —

DimensionBasicMaxMinTolerance
Major diameter D1Crest of the external thread2.37452.36220.0123
Pitch diameter E1Hand-tight plane, L1 from the small end (E1)2.313382.317842.308920.00892
Minor diameter K1Root of the external thread2.26822.25570.0125
Crest truncation fcFig. 2, both threads0.00430.0026
Root truncation frFig. 2; at least the mating crest’s maximum0.00610.0043
Crest flat FcEquivalent width of flat (Fig. 2)0.0050.003
Root flat FrEquivalent width of flat (Fig. 2)0.0070.005

Dimensions in inches. Values are those of the standard (ASME B1.20.3); calculated cells follow the standard’s formulas. Where the standard prints a value that differs from its formula, the printed value is shown with a note.

Diameters along the taper D major, E pitch, K minor (Table A1 notation), inches

PlaneE basicE maxE minD basicD maxD minK basicK maxK min
Plane 02.287942.292402.283482.34292.34912.33672.23652.24272.2302
Plane 12.313382.317842.308922.36832.37452.36222.26192.26822.2557
Plane 22.326752.331212.322292.38172.38792.37552.27532.28162.2690

The standard defines no basic major or minor diameter: D basic and K basic are calculated with the mean Fig. 2 truncations. On the taper every diameter changes by 0.0625 in. per inch of length.

Taper, lengths and gaging

Taper, gage and sealing para. 1.6, Fig. 1, Fig. 2

Taper on the diameter T
0.0625 ± 0.0050 in/in
Half apex angle of the pitch cone β
1° 47′ 24″
Included taper angle 2β
3° 34′ 47″
Taper on the radius
0.03125 in/in
Taper per thread on the diameter
0.004464 in
Gage tolerance, plus / minus ±
1 / 1 turns
Gage reference plane
Hand-tight plane, L1 from the small end (E1)
PD tolerance basis
Plus or minus the taper of one thread on the diameter (para. C.6)
Lead angle at the basic PD λ
0° 34′
Crest/root interference at flank contact, min – max δ
0.0000 – 0.0035 in
Recommended mating thread
F-PTF internal of the same size (full length, C.4)

Basic pitch diameters and lengths

Pitch dia at the small end of the external thread E0
2.28794 informula gives 2.28795
Pitch dia at the hand-tight plane E1
2.31338 informula gives 2.31339
Pitch dia at L2 E2
2.32675 informula gives 2.32679
Pitch dia at the small end of the internal thread E3
2.27455 in
Hand engagement L1
0.4070 · 5.70 in, turns
Wrench make-up L3
0.2143 · 0.01339 in, PD interference
Full external thread L2
0.621 · 8.7 in, threads
Vanish threads V
0.25 · 3.5 in, threads
Shoulder length Ls
0.8714 in
External thread for draw
0.2143 · 3 in, threads
OD of fitting D2
2.387 in

Notes

  • Fine series: the thread pitch of the next smaller pipe size applied to the next larger size; full length external and internal threads (C.4). Table C1 pipe OD column is cut off at the page edge in the PDF; the value is completed from Table 3 and confirmed by E0 = D - (0.05D + 1.1)p. Limits at the gage plane are calculated: pitch diameter from the basic PD and the gage tolerance in turns x 0.0625p; major and minor diameters from the pitch-diameter limits, H = 0.866025p and the Fig. 2 truncation limits.
  • DIFFERS: Fig. 2 prints H = 0.06180 for 14 threads per inch; 0.866025p = 0.061859, so the printed value is a misprint (0.06180 for 0.06186). The formula value is used for every calculation; Table B1 also reproduces only with 0.06186. || Rounding only (last digit): Table C1 E0: printed 2.28794, formula gives 2.28795 (-0.00001; E0 = D - (0.05D + 1.1)p (C.6)) | Table C1 E1: printed 2.31338, formula gives 2.31339 (-0.00001; E1 = E0 + 0.0625 L1 = D - 0.8625p (C.6 prints D - 0.0625p, a misprint)) | Table C1 E2: printed 2.32675; exact formula gives 2.32679 (-0.00004). The printed value is E0 + 0.0625 x the printed L2, which is rounded to 3 places, so this is rounding.

Mates

2-14 F-PTF screws into a thread of the same standard at the same size and pitch. The standard mating internal thread is class —. Check the fit with the standard pair →

Working out the mating options…

Different pitch or a different thread family never mate; the fit check runs over both tolerance zones.

Related thread sizes

Same diameter other pitch, and neighbouring sizes

→ 2-11.5 NPTF→ 2-11.5 PTF-SAE-SHORT→ 2-11.5 PTF-SPL-SHORT→ 2-11.5 PTF-SPL-EXTRA-SHORT→ 1 1/2-14 F-PTF→ 2-14 F-PTF internal
All values for 2-14 F-PTFevery column of the workbook row
All values of the workbook row 2-14 F-PTF
Designation2-14 F-PTF
Alternate designation2.3750 OD-14 F-PTF
Threads per inch14
Thread formDryseal 60°, taper 1:16
Series (Table 1)F-PTF
Series nameDryseal Fine Taper Pipe Thread
External / internalExternal
Class—
Nominal size2
Pitch P (in.)0.07142857
Pipe OD D, basic size (in.)2.375
Size categorySpecial series (Appendix C)
Source tableTable C1
Printed page18
Thread type (para. 1.2)App. C.4
Gage (reference) plane for the limitsHand-tight plane, L1 from the small end (E1)
Basic pitch dia at gage plane (in.)2.31338
Gage tolerance plus (turns)1
Gage tolerance minus (turns)1
PD tolerance basisPlus or minus the taper of one thread on the diameter (para. C.6)
Major dia max, D at gage plane (in.)2.3745
Major dia min, D at gage plane (in.)2.3622
Major dia tolerance, D (in.)0.0123
Pitch dia max, E at gage plane (in.)2.31784
Pitch dia min, E at gage plane (in.)2.30892
PD tolerance, E (in.)0.00892
Minor dia max, K at gage plane (in.)2.2682
Minor dia min, K at gage plane (in.)2.2557
Minor dia tolerance, K (in.)0.0125
Allowancenone (para. 1.3.2)
Root radiusnot specified; crests and roots may be rounded within the Fig. 2 truncation limits (para. 1.6)
Lead variation ±not given in B1.20.3 (gaging, B1.20.5)
Half-angle variation ±not given in B1.20.3 (gaging, B1.20.5)
Lead angle at basic PD (deg)0.5631
Lead angle (deg min)0° 34′
Stress areanot given in the standard
Thread angle (deg)60
Flank angle (deg)30
Sharp V height H (in.)0.061859
H as printed, Fig. 2 (in.)0.0618
Thread height h max (in.)0.054959
Thread height h min (in.)0.051459
Crest truncation min (in.)0.0026
Crest truncation max (in.)0.0043
Root truncation min (in.)0.0043
Root truncation max (in.)0.0061
Crest flat min (in.)0.003
Crest flat max (in.)0.005
Root flat min (in.)0.005
Root flat max (in.)0.007
Sweep cut: start diameter at gage plane (in.)2.3745
Sweep cut: tip diameter at gage plane (in.)2.2682
Sweep cut: depth (in.)0.05315
Sweep cut: tip flat (in.)0.0070
Sweep cut: profile width at start diameter (in.)0.06837
Crest flat as modelled (in.)0.00306
Sweep cut: taper on diameter (in./in.)0.0625
Check against formulasDIFFERS: Fig. 2 prints H = 0.06180 for 14 threads per inch; 0.866025p = 0.061859, so the printed value is a misprint (0.06180 for 0.06186). The formula value is used for every calculation; Table B1 also reproduces only with 0.06186. || Rounding only (last digit): Table C1 E0: printed 2.28794, formula gives 2.28795 (-0.00001; E0 = D - (0.05D + 1.1)p (C.6)) | Table C1 E1: printed 2.31338, formula gives 2.31339 (-0.00001; E1 = E0 + 0.0625 L1 = D - 0.8625p (C.6 prints D - 0.0625p, a misprint)) | Table C1 E2: printed 2.32675; exact formula gives 2.32679 (-0.00004). The printed value is E0 + 0.0625 x the printed L2, which is rounded to 3 places, so this is rounding.
NotesFine series: the thread pitch of the next smaller pipe size applied to the next larger size; full length external and internal threads (C.4). Table C1 pipe OD column is cut off at the page edge in the PDF; the value is completed from Table 3 and confirmed by E0 = D - (0.05D + 1.1)p. Limits at the gage plane are calculated: pitch diameter from the basic PD and the gage tolerance in turns x 0.0625p; major and minor diameters from the pitch-diameter limits, H = 0.866025p and the Fig. 2 truncation limits.
Taper on diameter (in./in.)0.0625
Taper tolerance ± (in./in.)0.0050
Half apex angle of pitch cone β (deg)1.7899
β (deg min sec)1° 47′ 24″
Included taper angle 2β (deg)3.5798
2β (deg min sec)3° 34′ 47″
Taper on radius (in./in.), 1 in 320.03125
β min from taper tolerance (deg)1.6468
β max from taper tolerance (deg)1.9330
Taper per thread on dia, 0.0625p (in.)0.004464
E0: PD at small end of external thread (in.)2.28794
E1: PD at hand-tight plane (in.)2.31338
E2: PD at L2, Table 3 (in.)2.32675
E3: PD at small end of internal, L1 + L3 (in.)2.27455
PD at end of this full external thread (in.)2.32675
PD at small end of external, max (in.)2.29240
PD at small end of external, min (in.)2.28348
Plane 0: distance from small end (ext) or face (int) (in.)0.0000
E0 basic: pitch dia at plane 0 (in.)2.28794
E0 max (in.)2.29240
E0 min (in.)2.28348
D0 basic, calculated (in.)2.3429
D0 max: major dia at plane 0 (in.)2.3491
D0 min (in.)2.3367
K0 basic, calculated (in.)2.2365
K0 max: minor dia at plane 0 (in.)2.2427
K0 min (in.)2.2302
Plane 1: distance from small end (ext) or face (int) (in.)0.4070
E1 basic: pitch dia at plane 1 (in.)2.31338
E1 max (in.)2.31784
E1 min (in.)2.30892
D1 basic, calculated (in.)2.3683
D1 max: major dia at plane 1 (in.)2.3745
D1 min (in.)2.3622
K1 basic, calculated (in.)2.2619
K1 max: minor dia at plane 1 (in.)2.2682
K1 min (in.)2.2557
Plane 2: distance from small end (ext) or face (int) (in.)0.6210
E2 basic: pitch dia at plane 2 (in.)2.32675
E2 max (in.)2.33121
E2 min (in.)2.32229
D2 basic, calculated (in.)2.3817
D2 max: major dia at plane 2 (in.)2.3879
D2 min (in.)2.3755
K2 basic, calculated (in.)2.2753
K2 max: minor dia at plane 2 (in.)2.2816
K2 min (in.)2.2690
Distance x measured fromsmall end of the external thread
PD change along x (+1 grows, −1 shrinks, 0 straight)1
E at x = 0, basic (in.)2.28794
Hand engagement L1 (in.)0.407
L1 (threads)5.7
Hand-tight engagement of this thread (in.)0.4070
Hand-tight engagement (turns)5.70
Wrench make-up L3 = 3p (in.)0.2143
PD interference from L3 make-up, on dia (in.)0.01339
Length of full external thread L2 (in.)0.621
Full external thread (threads)8.7
Vanish thds V + 1p + 1/2p (in.)0.25
V + 1p + 1/2p (threads)3.5
Shoulder length L2 + 3p approx. (in.)0.8714
External thread for draw (in.)0.2143
Draw (threads)3
OD of fitting D2 (in.)2.387
Crest/root interference at flank contact, min (radial, in.)0.0000
Crest/root interference at flank contact, max (radial, in.)0.0035
Recommended mating thread (Table 1, C.3)F-PTF internal of the same size (full length, C.4)
Lookup key2-14 F-PTF | External

Related tools

ASME B1.20.3: Dryseal Pipe Threads, Inch. Source: workbook data (2026-10-10). Confirm against your licensed copy of the standard before use.