THK square fixed-side support unit for ball screws with a 40 mm bearing journal diameter.
The BK40 contains a factory-preloaded P5 angular-contact bearing set in a DF arrangement, providing accurate shaft positioning and high axial rigidity. Its compact housing allows straightforward installation without additional bearing adjustment.
The unit is supplied complete with its housing, bearing set, holding lid, collars, seals, lock nut and locking screw.
Product characteristics
Category: Ball screw support units
Manufacturer: THK
Series: BK
Design: Square support unit
Mounting position: Fixed side
Bearing journal diameter: 40 mm
Bearing arrangement: DF angular-contact arrangement
Bearing accuracy: P5
Bearing used: 7208 equivalent
Preload: Factory adjusted
Weight: 6.500 kg
Country of origin: Japan
Main dimensions
Shaft diameter d: 40 mm
Length L: 61 mm
L1: 18 mm
L2: 76 mm
L3: 15 mm
Housing width B: 160 mm
Housing height H: 110 mm
Housing thickness b: 80 mm
Shaft centre height h1: 60 mm ±0.02 mm
B1: 100 mm
H1: 90 mm
E: 37 mm
Mounting-hole pitch P: 130 mm
C1: 33 mm
C2: 14 mm
Square dimension T: 50 mm
Mounting-hole dimensions
Through-hole diameter d1: 18 mm
Counterbore diameter d2: 26 mm
Counterbore depth h: 17.5 mm
Holding-lid thread M: M8
Collar dimensions
Collar outside diameter D: 49.4 mm
Collar thickness t: 15 mm
Load ratings
Basic dynamic axial load rating Ca: 44.1 kN
Static permissible axial load: 27.1 kN
Axial rigidity: 270 N/μm
Components supplied
Housing: 1
Precision bearing set: 1
Holding lid: 1
Collars: 2
Seals: 2
Lock nut: 1
Hexagonal socket-head locking screw with set piece: 1
The BK40 is designed for the fixed end of a ball screw and can be paired with a THK BF40 supported-side unit.
Spend over £50 (excl VAT) and your Shipping is FREE. UK Mainland Only.
We offer a range of shipping options to suit you.
Royal Mail Standard Shipping
£2.00 - Our cheapest shipping method for parcels up to 500g. Parcels are sent using the Royal Mail standard shipping service and usually take 2-5 working days to arrive. This service isn’t tracked at any stage until point of delivery.
Royal Mail Tracked 48
£4.00 - For parcels weighing up to 2kg. Royal Mail aims to deliver within 2–3 working days from the date your order is dispatched, not from the date you place your order. Once dispatched, you’ll receive an email from Royal Mail containing full tracking details.
Next Working Day – UK Mainland Only
£8.50 – Orders placed before 4pm will be received the next working day, Monday to Friday. You will receive an email from the courier with full tracking details. We tend to use UPS, DPD or Royal Mail Next Day.
Northern Ireland 2 Day Service
£15.00 – This is a two day service to Northern Ireland. You will receive an email from the courier with full tracking details. We tend to use UPS, DPD or Royal Mail.
Northern Ireland Next Day Service
£35.00 - This is a next day service to Northern Ireland. You will receive an email with full tracking details. We tend to use UPS, DPD or Royal Mail Next Day.
Next Working Day AM – Pre 12 UK Mainland Only
£20.00 - Orders placed before 4pm will be received the next working day before Midday. You will receive an email from the courier with full tracking details. We tend to use UPS, DPD or Royal Mail.
Next Working Day AM – Pre 10.30 UK Mainland Only
£25.00 - Orders placed before 4pm will be received the next working day before 10.30am. You will receive an email from the courier with full tracking details.
Scottish Islands 2-3 Day Service
£25.00 - This is a two to three day service. You will receive an email from the courier with full tracking details.
Scottish Highlands 2-3 Day service
£35.00 - This is a two to three day service. You will receive an email from the courier with full tracking details.
SAME DAY TAXI – Please call 01709 527269 for a quote and we will try to accommodate where possible.
Click and Collect
FREE - We offer a Click & Collect service for customers that are able to collect from our premises at Bearing King. Unit 5, Northfield Business Park, Parkgate, Rotherham S60 1SD United Kingdom.
Please note, you will be notified by email when your order is available for collection. Do not set off to collect your order until you have received the email notification that the order is ready for collection.
Shipping Internationally – Europe and Rest of the World
We offer a range of options for shipping around the world. These choices will be displayed dependent on your shipping location once the item is in your basket and you are ready to Checkout.
Returns Policy
1. You may return an unused item in new condition unless faulty within 30 days of receipt. Damaged or used goods cannot be refunded.
2. A copy of our returns form must be included with the returned goods.
3. Customers will be responsible for the original and return shipping charges unless our customer service department determines that we are at fault for an order error or product defect. Bearing King will not be responsible for any return item lost in transit.
4. Once we receive the package and the goods are checked, we will refund you by the payment method used when the order was placed.
5. Please allow 3-5 days for your return to be processed or exchange to be sent.
