G R Rp Whitworth Thread BSPP BSPT

Reference data and engineering information about g r rp whitworth thread bspp bspt for miscellaneous applications.

WhitworththreadBSPPBSPT

Overview

Engineering reference data for G R Rp Whitworth Thread BSPP BSPT in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Thread Specifications

The Whitworth thread profile defines these key geometric properties where p represents the pitch:

Thread angle: 55°
Thread depth: $0.640327p$
Root radius: $0.137329p$

BSPP (G) Thread Dimensions

8 rows

British Standard Pipe Parallel (BSPP) thread dimensions. TPI = Threads Per Inch.
Thread Size (inch)	Major Diameter(mm)	Minor Diameter(mm)	TPI
G 1/16	7.723	6.561	28
G 1/8	9.728	8.566	28
G 1/4	13.157	11.445	19
G 3/8	16.662	14.95	19
G 1/2	20.955	18.631	14
G 3/4	26.441	24.117	14
G 1	33.249	30.291	11
G 2	59.614	56.656	11

Source: engineeringtoolbox.com

BSPT (R/Rp) Thread Dimensions

8 rows

British Standard Tapered Pipe (BSPT) thread dimensions. TPI = Threads Per Inch.
Male Thread Size (inch)	Female Thread Size (inch)	Major Diameter(mm)	Minor Female Diameter(mm)	TPI
R 1/16	Rp 1/16	7.723	6.49	28
R 1/8	Rp 1/8	9.728	8.495	28
R 1/4	Rp 1/4	13.157	11.341	19
R 3/8	Rp 3/8	16.662	14.846	19
R 1/2	Rp 1/2	20.955	18.489	14
R 3/4	Rp 3/4	26.441	23.975	14
R 1	Rp 1	33.249	30.111	11
R 2	Rp 2	59.614	56.476	11

Source: engineeringtoolbox.com

Sealing Mechanisms

BSPT connections seal through thread engagement. The male BSPT (R) thread seals directly against the female BSPT (Rp) thread.

BSPP connections require a different sealing method. BSPT (R) or BSPP (G) male threads with a conical 30° seat seal against a matching conical 30° seat on a BSPP female swivel fitting.