Data Sheet 2 Power Screw Products Kingston Engineering has been manufacturing Right Hand/Left Hand, single/multi-start, cut thread Power Transmission Screws and Nuts for over 60 years and currently offers a full range of thread forms suitable for mechanical power transmission, all conforming to British, European or American Standards. Our nominal capacity range for Screw products is 10 to 200 mm diameter by 6 metres (3/8? to 8? dia by 20’) length in one piece, but any practical length with seamless jointing. For Nuts we can accommodate up to 1 metre diameter and 2,000 kg (40? dia and 4,400 lbs). Full associated machining services are available from our comprehensive workshops. For the efficient transmission of power, imperial based Acme and metric based Trapezoidal thread forms are very similar and by far the most common in use. To assist in the choice where these thread forms would satisfy your application, we show overleaf two Screw Selection Tables. Both tables show recommended maximum values based on good quality, medium carbon steel to 080M40, single start Screws and SAE660 Phosphor Bronze or Grade 250 Cast Iron Nuts, with good surface finish to all thread flank faces and a factor of safety of 2. In practice it is advisable to keep well inside these recommended maximum figures. For general engineering applications we offer our Stock Range of Acme and Trapezoidal Power Screws and Nuts. This provides an economic, off-the-shelf choice covering 12mm to 60mm diameter and 0.5? to 2.50? dia screws available at a length to suit your application and each with a full range of compatible nuts. Please click on Data Sheet 3 - Standard Screw Stock, which gives full details. Where your application is for a specific requirement, for example Multi-Start, Modified Square, Stub Acme or Buttress thread forms, or is outside the range of the tables, please speak to our Technical Sales staff who will be pleased to advise, aided by our own Screw Design Software and many years, broad, practical experience. We promise a speedy response to your quotation request, are committed to maintaining delivery promises, and will not willingly be beaten on price for components within our normal capacity. Other Screw related products - Self-reversing Screw and Follower assemblies - used for the level winding of line, rope, cable and hawser on to storage drums. Nominal manufacturing capacity similar to that for Power Transmission Screws. - Special purpose applications - for example: - Product feed screws - with variable pitch if required. Finned cooling tubes. Telescopic screw assemblies. Multi-start valve actuator assemblies. Pen Stock screw assemblies. Screw Selection Tables For assistance please ring Kingston Screw Sales on +44 (0)1482 325676 and speak to our technical sales staff. Table 1 - This table show the maximum recommended axial load on the Screw/Nut assembly for various screws across a range of axial speeds. The table is based on providing the Maximum Allowable Bearing Pressure between Screw and Nut, which is the most common limiting factor, whilst still achieving a reasonable working life. Table 1a - Example (Acme threads - table figures in lb.) Find suitable screw to move 500 lb vertically at a speed of 45"/min. From the table the 48"/min. column shows that a 1" diameter by 5 TPI (Teeth per Inch) is suitable for loads up to 730 lbs  Table 1b - Example (Trapezoidal threads - table figures in kg.) Find suitable screw to move 200 kg vertically at a speed of 1,100 mm per min. From the table the 1,200 mm per min. column shows that a 25 mm diameter by 5 mm pitch is suitable for loads up to 330 kg.  Table 2 - This table shows the maximum recommended axial load (in lbs) on the Screw /Nut assembly for various screws across a range of unsupported lengths (in inches), to avoid buckling when the Screw is loaded in compression and is acting as a column.  © Kingston Engineering Co (Hull) Ltd. No liability can be accepted for any loss or damage resulting from the use of the above information |
