BA THREAD

Descriptions

BA (British Association) threads are a British standard for small screws and fasteners, primarily used in precision instruments, model engineering, and legacy electrical equipment. Unlike metric threads, they are designated by a number (e.g., 0BA, 2BA, 4BA), where a higher number indicates a smaller diameter.

Key Characteristics

Thread Angle: BA threads have a unique, symmetrical V-profile with a 47.5° flank angle. This differs from the 60° angle used by metric and Unified threads, making them non-interchangeable.
Thread Profile: The threads feature rounded crests and roots to reduce stress concentrations and enhance durability in delicate applications.
Sizing System: The system is based on a geometric progression, with the pitch of each successive size (higher number) being approximately 0.9 times the pitch of the lower number.
Standardization: They are specified by British Standard BS 93:2008, which defines dimensions and tolerances for sizes 0BA to 16BA.

Specifications

No detailed specifications are available for this product.

Downloads

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Code	Description	Price	Quantity
BMSBA0037CS	OBA X 3/8 BRASS CSK SLOTTED MACHINE SCREW 2600 In Stock for despatch	Price Unavailable	- +
BMSBA0050CS	*0BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£633.05 (exc VAT) per THOU £759.66 (inc VAT)	- +
BMSBA0062CS	*OBA X 5/8 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£1,001.50 (exc VAT) per THOU £1,201.80 (inc VAT)	- +
BMSBA0075CS	*0BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£950.00 (exc VAT) per THOU £1,140.00 (inc VAT)	- +
BMSBA0100CS	*0BA X 1" BRASS CSK SLOTTED MACHINE SCREW 71 In Stock for despatch	£1,660.00 (exc VAT) per THOU £1,992.00 (inc VAT)	- +
BMSBA0150CS	*OBA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW 79 In Stock for despatch	£1,645.07 (exc VAT) per THOU £1,974.08 (inc VAT)	- +
BMSBA0200CS	*0BA X 2" BRASS CSK SLOTTED MACHINE SCREW 100 In Stock for despatch	£1,473.33 (exc VAT) per THOU £1,768.00 (inc VAT)	- +
BMSBA0300CS	0BA X 3" BRASS CSK SLOTTED MACHINE SCREW 200 In Stock for despatch	Price Unavailable	- +
BMSBA1050CS	1BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 160 In Stock for despatch	£4,779.37 (exc VAT) per THOU £5,735.24 (inc VAT)	- +
BMSBA1100CS	1BA X 1" BRASS CSK SLOTTED MACHINE SCREW 100 In Stock for despatch	Price Unavailable	- +
BMSBA1150CS	*1BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£1,277.00 (exc VAT) per THOU £1,532.40 (inc VAT)	- +
BMSBA1200CS	*1BA X 2" BRASS CSK SLOTTED MACHINE SCREW 24 In Stock for despatch	Price Unavailable	- +
BMSBA2037CS	*2BA X 3/8 BRASS CSK SLOTTED MACHINE SCREW 150 In Stock for despatch	Price Unavailable	- +
BMSBA2050CS	*2BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 47 In Stock for despatch	£283.22 (exc VAT) per THOU £339.86 (inc VAT)	- +
BMSBA2062CS	2BA X 5/8 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	Price Unavailable	- +
BMSBA2075CS	*2BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW 80 In Stock for despatch	£427.00 (exc VAT) per THOU £512.40 (inc VAT)	- +
BMSBA2100CS	*2BA X 1" BRASS CSK SLOTTED MACHINE SCREW 111 In Stock for despatch	£950.00 (exc VAT) per THOU £1,140.00 (inc VAT)	- +
BMSBA2150CS	*2BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£810.00 (exc VAT) per THOU £972.00 (inc VAT)	- +
BMSBA2200CS	*2BA X 2" BRASS CSK SLOTTED MACHINE SCREW 34 In Stock for despatch	£1,292.54 (exc VAT) per THOU £1,551.05 (inc VAT)	- +
BMSBA2250CS	*2BA X 2.1/2 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£1,237.20 (exc VAT) per THOU £1,484.64 (inc VAT)	- +
BMSBA2300CS	*2BA X 3" BRASS CSK SLOTTED MACHINE SCREW 110 In Stock for despatch	Price Unavailable	- +
BMSBA3050CS	3BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 460 In Stock for despatch	£78.43 (exc VAT) per THOU £94.12 (inc VAT)	- +
BMSBA3075CS	*3BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£450.00 (exc VAT) per THOU £540.00 (inc VAT)	- +
BMSBA3100CS	*3BA X 1" BRASS CSK SLOTTED MACHINE SCREW 200 In Stock for despatch	Price Unavailable	- +
BMSBA3150CS	*3BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW 140 In Stock for despatch	Price Unavailable	- +
BMSBA3200CS	3BA X 2" BRASS CSK SLOTTED MACHINE SCREW 110 In Stock for despatch	Price Unavailable	- +
BMSBA4019CS	*4BA X 3/16 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£573.60 (exc VAT) per THOU £688.32 (inc VAT)	- +
BMSBA4025CS	*4BA X 1/4 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£174.30 (exc VAT) per THOU £209.16 (inc VAT)	- +
BMSBA4031CS	*4BA X 5/16 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£434.30 (exc VAT) per THOU £521.16 (inc VAT)	- +
BMSBA4037CS	*4BA X 3/8 BRASS CSK SLOTTED MACHINE SCREW 2470 In Stock for despatch	Price Unavailable	- +
BMSBA4050CS	*4BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 280 In Stock for despatch	£463.60 (exc VAT) per THOU £556.32 (inc VAT)	- +
BMSBA4062CS	*4BA X 5/8 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£552.10 (exc VAT) per THOU £662.52 (inc VAT)	- +
BMSBA4075CS	*4BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW 88 In Stock for despatch	Price Unavailable	- +
BMSBA4100CS	*4BA X 1" BRASS CSK SLOTTED MACHINE SCREW 340 In Stock for despatch	£240.74 (exc VAT) per THOU £288.89 (inc VAT)	- +
BMSBA4150CS	*4BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW 5 In Stock for despatch	£576.00 (exc VAT) per THOU £691.20 (inc VAT)	- +
BMSBA4200CS	*4BA X 2" BRASS CSK SLOTTED MACHINE SCREW 80 In Stock for despatch	£143.23 (exc VAT) per THOU £171.88 (inc VAT)	- +
BMSBA4300CS	*4BA X 3" BRASS CSK SLOTTED MACHINE SCREW 30 In Stock for despatch	Price Unavailable	- +
BMSBA5037CS	*5BA X 3/8 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£383.20 (exc VAT) per THOU £459.84 (inc VAT)	- +
BMSBA5050CS	*5BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 50 In Stock for despatch	£2,500.00 (exc VAT) per THOU £3,000.00 (inc VAT)	- +
BMSBA5075CS	*5BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£350.00 (exc VAT) per THOU £420.00 (inc VAT)	- +
BMSBA5150CS	5BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW 26 In Stock for despatch	£468.52 (exc VAT) per THOU £562.22 (inc VAT)	- +
BMSBA5200CS	*5BA X 2" BRASS CSK SLOTTED MACHINE SCREW 475 In Stock for despatch	Price Unavailable	- +
BMSBA6025CS	*6BA X 1/4 BRASS CSK SLOTTED MACHINE SCREW 100 In Stock for despatch	Price Unavailable	- +
BMSBA6037CS	*6BA X 3/8 BRASS CSK SLOTTED MACHINE SCREW 400 In Stock for despatch	Price Unavailable	- +
BMSBA6050CS	*6BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 445 In Stock for despatch	£800.00 (exc VAT) per THOU £960.00 (inc VAT)	- +
BMSBA6075CS	*6BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW 480 In Stock for despatch	Price Unavailable	- +
BMSBA6100CS	*6BA X 1" BRASS CSK SLOTTED MACHINE SCREW 20 In Stock for despatch	£300.00 (exc VAT) per THOU £360.00 (inc VAT)	- +
BMSBA6150CS	*6BA X 1.1/2 BRASS CSK SLOTTED MACHINE SCREW 25 In Stock for despatch	£392.00 (exc VAT) per THOU £470.40 (inc VAT)	- +
BMSBA7050CS	7BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 20 In Stock for despatch	£1,900.00 (exc VAT) per THOU £2,280.00 (inc VAT)	- +
BMSBA7100CS	7BA X 1" BRASS CSK SLOTTED MACHINE SCREW 900 In Stock for despatch	£950.00 (exc VAT) per THOU £1,140.00 (inc VAT)	- +
BMSBA8019CS	8BA X 3/16 BRASS CSK SLOTTED MACHINE SCREW 400 In Stock for despatch	Price Unavailable	- +
BMSBA8050CS	*8BA X 1/2 BRASS CSK SLOTTED MACHINE SCREW 1260 In Stock for despatch	Price Unavailable	- +
BMSBA8075CS	*8BA X 3/4 BRASS CSK SLOTTED MACHINE SCREW Out of Stock	£460.00 (exc VAT) per THOU £552.00 (inc VAT)	- +

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