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2.500 In. Diameter - 0.500 In. Lead

This 2.500 inch diameter ball screw has a 0.500 inch lead. Corresponding standard capacity ball nuts with right-hand threads are available.

Ball screw specifications	RH
Ball screw part no.	BS 250 R 050 A
Nominal ball circle diameter	2.500 in.
Lead	0.500 in.
Screw diameter	2.540 in.
Root diameter	2.220 in.
Screw weight	14.98 lb./ft.
Torque to raise 1 pound*	0.089in.-lb.
Maximum screw length	24 ft.

* Torque to raise 1 pound = 0.177 x inches lead x pounds load

Standard Capacity Ball Nut Specifications (S)

Ball nut specifications	RH
Ball nut part no. (standard capacity)	BN 250 R 050 S
Ball nut with flange part no.	BF 250 R 050 S
Dynamic load capacity**	22,000 lb.
Static load capacity	155,500 lb.
Ball nut weight	12.09 lb.
Nominal ball dia. (avg. ball qty.)	3/8 in. (186)
Flange part no.	FL-3625
Wiper kit part no.	WK-70

** for 1,000,000 inches

High Capacity Ball Nut Specifications (H)

Ball nut specifications	RH
Ball nut part no. (standard capacity)	BN 225 R 050 H
Ball nut with flange part no.	BF 225 R 050 H
Dynamic load capacity**	29,700 lb.
Static load capacity	213,000 lb.
Ball nut weight	11.22 lb.
Nominal ball dia. (avg. ball qty.)	3/8 in. (237)
Flange part no.	FL-3137
Wiper kit part no.	WK-60

** for 1,000,000 inches

2D/3D Drawings

Product Media

2D/3D DRAWINGS 2.500" X .500" DATA SHEET SB BEARING BLOCKS AND SCREW ENDS DB BEARING BLOCKS AND SCREW ENDS FB BEARING BLOCKS AND SCREW ENDS STANDARD BALL NUT, FLANGE, WIPER KIT EFFECT OF CHANGE IN PARAMETER

Ball screws are made from alloy steel and case hardened to Rc56 (minimum).
A black oxide finish is applied to prevent corrosion during shipping and for a brief storage period.
The rust inhibiting properties of the screw lubricant offers additional corrosion resistance.
Ball nut housings are steel with case hardened threads. A black oxide coating provides additional protection.
Flanges are constructed of steel with a black oxide coating.

Sample Part Number:

Click on the part number to reveal additional information about the screw design and shaft codes.

Thread Form

B: Ball Screw

Component

A: Assembly
S: Screw - without ball nut or bearing mounts

Screw Diameter - Thread direction - TPI (English)

Dia/TPI	Code
5/8 - .200*	063 R 020
3/4 - .200	075 R 020
3/4 - .500	075 R 050
1 - .250*	100 R 025
1 - .500	100 R 050
1 - 1.000	100 R 100
1 1/2 - .500	150 R 050
1 1/2 - 1.00	150 R 100
1 1/2 - 1.875	150 R 188
2 1/4 - .500	225 R 050
2 1/2 - .500	250 R 050
3 - .660	300 R 066
4 - 1.000	400 R 100

R – Right-hand – all thread diameters/leads are available with right hand threads
L – Left-hand *- Substitute an ”L” in the part number for left hand leads

Screw Material

A: Alloy Steel

First End of Screw

(Flange or threaded end of nut always faces second end)

Bearing Mount Options	Machining Options (choose one that corresponds to the bearing block)
SB - Simple Single*	1N – Threaded shaft only
DB - Simple Double	2K – Thd Shaft w Kwy, 2L – Thd Shaft no Kwy, 2N – Threaded shaft only
FB - Fixed Double	3K – Thd Shaft w Kwy, 3L – Thd Shaft no Kwy, 3N – Threaded shaft only
XX - No Bearing	4K – Shaft w Keyway, 4L – Shaft no Keyway, 4N – Support only, XX – No Machining

(When selecting ”XX – No Bearing”, choose from mounting options 1K through 4N or XX, above)
* All Simple Single bearing mounts are designed for radial loads only

Second End of Screw

(Flange or threaded end of nut always faces away from second end)

Bearing Mount Options	Machining Options (choose one that corresponds to the bearing block)
SB - Simple Single*	1N – Threaded shaft only
DB - Simple Double	2K – Thd Shaft w Kwy, 2L – Thd Shaft no Kwy, 2N – Threaded shaft only
FB - Fixed Double	3K – Thd Shaft w Kwy, 3L – Thd Shaft no Kwy, 3N – Threaded shaft only
XX - No Bearing	4K – Shaft w Keyway, 4L – Shaft no Keyway, 4N – Support only, XX – No Machining

(When selecting ”XX – No Bearing”, choose from mounting options 1K through 4N or XX, above)
* All Simple Single bearing mounts are designed for radial loads only

Ball Nut Properties

S - Standard Capacity
H - High Capacity
U - Ultra Capacity
X - No ball nut

Other Options

F - With Flange
B - With Flange and Wipers
W - Wipers
X - No Options

Screw Length 000.00"

Enter value in inches with decimal if needed
Note that available screw length varies among screw sizes.

SB Screw End Conditions

jack

Screw Number	Bearing Mount No.	oS1	A1	A2	A3	A4	A5	A6	o A7	A8	A9	A10	A11
BS250R050A		2.1659	1.770	1.120	0.86	0.315	1.142	2.225	4.13	2.157-18 UNS	W-11	N-11	6311
		2.1653	1.770	1.120	0.86	0.313	1.142	2.225	4.13	2.157-18 UNS	W-11	N-11	6311

DB Screw End Conditions

jack

Screw Number	Bearing Mount No.	oS1	oS2	A1	A2	A3	A4	A5	A6	A7	A8	A9
BS250R050A		2.1659	1.875	8.40	5.40	4.700	1.142	0.063	2.157-18 UNS	W-11	N-11	1/2 x 1 1/2
		2.1653	1.874	8.40	5.40	4.700	1.142	0.063	2.157-18 UNS	W-11	N-11	1/2 x 1 1/2

FB Screw End Conditions

jack

Screw Number	Bearing Mount No.	oS1	oS2	A1	A2	A3	A4	A5	A6	A7	A8	A9	A10	A11
BS250R050A		2.1659	1.875	10.10	7.35	6.50	5.608	1.142	3.350	0.035	2.157-18 UNS	W-11	N-11	1/2 x 1 1/2
		2.1653	1.874	10.10	7.35	6.50	5.608	1.142	3.350	0.035	2.157-18 UNS	W-11	N-11	1/2 x 1 1/2

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