Machine Screws - Slotted Countersunk - BA

A machine screw is a type of screw that is commonly used in industrial and manufacturing applications to secure components within engines, electronic products and general machinery.

Countersunk machine screws are designed for installation in countersunk holes to enable them to sit flush within the finished surface. This type of fastener should be installed with a flat-bladed screwdriver or bit.

They are available in zinc plated, brass and stainless-steel finishes.

About BA Thread

BA thread (British association) is a rarely used thread that was once commonly found on small instruments and models. Still sparingly used in some industries such as metering equipment manufacturing and optical equipment.

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Machine Screws - Slotted Countersunk - BA
Guides & Tips

4BA x 5/8" Countersunk Slotted Machine Screw BS 57 - A2 Stainless Steel - Pack of 10

CODE: MSBASCA204062

£16.09 £19.31

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

A2 Stainless Steel

Finish:

Stainless Steel

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

5/8"

MORE INFO

4BA x 3/4" Countersunk Slotted Machine Screw BS 57 - A2 Stainless Steel - Pack of 10

CODE: MSBASCA204075

£17.70 £21.24

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

A2 Stainless Steel

Finish:

Stainless Steel

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

3/4"

MORE INFO

6BA x 1" - Machine Screw Countersunk Slotted BS 57 - A2 Stainless Steel - Pack of 10

CODE: MSBASCA206100

£21.23 £25.48

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

A2 Stainless Steel

Finish:

Stainless Steel

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

MORE INFO

2BA x 1" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR02100

£13.10 £15.72

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

MORE INFO

4BA x 3/16" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR04018

£11.02 £13.22

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

3/16"

MORE INFO

4BA x 1/4" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR04025

£11.02 £13.22

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

1/4"

MORE INFO

5BA x 3/8" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR05037

£18.88 £22.66

Pitch:

0.59P

Threads Per Inch:

43.1

Diameter:

0.126"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.65mm

Total Length:

3/8"

MORE INFO

6BA x 1/2" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR06050

£9.53 £11.44

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

1/2"

MORE INFO

6BA x 3/4" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR06075

£10.26 £12.31

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

3/4"

MORE INFO

6BA x 1" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR06100

£20.25 £24.30

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

MORE INFO

6BA x 1 1/4" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR06125

£23.87 £28.64

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

1 1/4"

MORE INFO

6BA x 1 1/2" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR06150

£23.35 £28.02

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

1 1/2"

MORE INFO

8BA x 1/4" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR08025

£9.67 £11.60

Pitch:

0.43P

Threads Per Inch:

59.1

Diameter:

0.086"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

1.8mm

Total Length:

1/4"

MORE INFO

8BA x 1" - Machine Screw Countersunk Slotted - Brass - Pack of 25

CODE: MSBASCBR08100

£30.20 £36.24

Pitch:

0.43P

Threads Per Inch:

59.1

Diameter:

0.086"

Material:

Brass

Finish:

Brass

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

1.8mm

Total Length:

MORE INFO

0BA x 1/2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC00050

£21.94 £26.33

Pitch:

1.00P

Threads Per Inch:

25.4

Diameter:

0.236"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

5.1mm

Total Length:

1/2"

MORE INFO

0BA x 7/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC00087

£9.31 £11.17

Pitch:

1.00P

Threads Per Inch:

25.4

Diameter:

0.236"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

5.1mm

Total Length:

7/8"

MORE INFO

1BA x 1" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC01100

£15.25 £18.30

Pitch:

0.90P

Threads Per Inch:

28.2

Diameter:

0.209"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4.5mm

Total Length:

MORE INFO

2BA x 5/16" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02031

£9.36 £11.23

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

5/16"

MORE INFO

2BA x 3/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02037

£10.71 £12.85

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

3/8"

MORE INFO

2BA x 1/2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 8

CODE: MSBASCSC02050

Only 1 pack left in stock

£8.30 £9.96

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1/2"

MORE INFO

2BA x 5/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02062

£10.94 £13.13

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

5/8"

MORE INFO

2BA x 3/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02075

£10.97 £13.16

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

3/4"

MORE INFO

2BA x 7/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 10

CODE: MSBASCSC02087

£17.92 £21.50

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

7/8"

MORE INFO

2BA x 1 1/2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 6

CODE: MSBASCSC02150

Only 1 pack left in stock

£6.27 £7.52

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1 1/2"

MORE INFO

2BA x 1 3/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02175

£11.53 £13.84

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1 3/4"

MORE INFO

2BA x 2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC02200

£11.87 £14.24

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

MORE INFO

3BA x 3/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC03075

£10.82 £12.98

Pitch:

0.73P

Threads Per Inch:

34.8

Diameter:

0.161"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3.4mm

Total Length:

3/4"

MORE INFO

3BA x 1" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC03100

£11.25 £13.50

Pitch:

0.73P

Threads Per Inch:

34.8

Diameter:

0.161"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3.4mm

Total Length:

MORE INFO

3BA x 2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC03200

£13.30 £15.96

Pitch:

0.73P

Threads Per Inch:

34.8

Diameter:

0.161"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3.4mm

Total Length:

MORE INFO

4BA x 3/16" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC04018

£9.28 £11.14

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

3/16"

MORE INFO

4BA x 1/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC04025

£9.33 £11.20

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

1/4"

MORE INFO

4BA x 3/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC04037

£9.65 £11.58

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

3/8"

MORE INFO

4BA x 1 1/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 9

CODE: MSBASCSC04125

Only 1 pack left in stock

£4.62 £5.54

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

1 1/4"

MORE INFO

4BA x 1 3/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC04175

£10.47 £12.56

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

1 3/4"

MORE INFO

4BA x 2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC04200

£11.05 £13.26

Pitch:

0.66P

Threads Per Inch:

38.5

Diameter:

0.142"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

3mm

Total Length:

MORE INFO

5BA x 1/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC05025

£13.11 £15.73

Pitch:

0.59P

Threads Per Inch:

43.1

Diameter:

0.126"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.65mm

Total Length:

1/4"

MORE INFO

6BA x 1/4" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC06025

£9.34 £11.21

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

1/4"

MORE INFO

6BA x 5/16" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC06031

£9.43 £11.32

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

5/16"

MORE INFO

6BA x 3/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 50

CODE: MSBASCSC06037

£9.46 £11.35

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

3/8"

MORE INFO

6BA x 1/2" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 50

CODE: MSBASCSC06050

£9.40 £11.28

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

1/2"

MORE INFO

6BA x 5/8" - Machine Screw Countersunk Slotted BS 57 - Self Colour - Pack of 25

CODE: MSBASCSC06062

£9.43 £11.32

Pitch:

0.53P

Threads Per Inch:

47.9

Diameter:

0.11"

Material:

Steel

Finish:

Self Colour

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

2.3mm

Total Length:

5/8"

MORE INFO

0BA x 3/8" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP00037

£29.71 £35.65

Pitch:

1.00P

Threads Per Inch:

25.4

Diameter:

0.236"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

5.1mm

Total Length:

3/8"

MORE INFO

0BA x 3/4" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP00075

£24.35 £29.22

Pitch:

1.00P

Threads Per Inch:

25.4

Diameter:

0.236"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

5.1mm

Total Length:

3/4"

MORE INFO

2BA x 1/4" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02025

£10.35 £12.42

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1/4"

MORE INFO

2BA x 1/2" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02050

£11.07 £13.28

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1/2"

MORE INFO

2BA x 3/4" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02075

£9.33 £11.20

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

3/4"

MORE INFO

2BA x 1" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02100

£22.93 £27.52

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

MORE INFO

2BA x 1 1/4" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02125

£12.14 £14.57

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1 1/4"

MORE INFO

2BA x 1 1/2" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02150

£13.08 £15.70

Pitch:

0.81P

Threads Per Inch:

31.4

Diameter:

0.185"

Material:

Steel

Finish:

Bright Zinc Plated and Clear Passivation

Head Type:

Countersunk Slotted

Thread Type:

Imperial - BA

Tapping Drill Size:

4mm

Total Length:

1 1/2"

MORE INFO

2BA x 2 1/2" - Machine Screw Countersunk Slotted BS 57 - BZP - Pack of 25

CODE: MSBASCZP02250

£12.87 £15.44