Buy A4 Stainless Coach Screws | M10 x 70mm A4 Stainless Lag Screws

M10 x 70mm A4 Stainless Hex Head Coach Screws DIN 571

A4 (316) Marine grade stainless steel

Rust resistant for exterior use

17mm Hexagon head

ORDER BY 3PM FOR NEXT DAY DELIVERY (MON-FRI)*

ORDER BY 3PM FOR NEXT DAY DELIVERY*

FREE STANDARD DELIVERY ON ORDERS OVER £100*

FREE STANDARD DELIVERY OVER £100*

Description
Delivery

What are Coach Screws?

A Guide to Marine Grade A4 Stainless Steel Lag Bolts and Their Uses

Coach screws (also known as lag screws or lag bolts) are essential heavy-duty fasteners primarily used in timber-to-timber construction. These robust screws feature a hexagonal head, making them ideal for high-torque applications. When you need extra strength and rust resistance for outdoor projects, A4 stainless steel coach screws are a top choice, especially in very corrosive environments such as coastal areas, applications exposed to chemicals i.e. swimming pools, or areas exposed to excessive temperature fluctuations.

Key Applications:

Securing metal plates or concrete posts to timber
Heavy-duty timber-to-timber applications
Fixing into masonry when used with a nylon plug
External applications, or for use in corrosive environments

Why Choose A4 316 Stainless Steel Coach Screws?

A4 (316) stainless steel is commonly known as 'marine grade' stainless steel, as it can be used in salt water environments
Ultimate rust resistance for outdoor use - A4 stainless has better rust resistance than A2 stainless
Stainless steel is essential when working with oak and other hardwoods with a high tannin content
Ideal for projects exposed to harsh weather or moisture, chemicals or heat exposure

Important Note: While stainless steel offers excellent corrosion resistance, it’s softer than carbon steel. For best results, always use a pilot drill, especially in hard woods like oak.

Specifics

Diameter (d1): Ø10mm (M10)
Length from under head (L): 70mm
Head height (k): 7mm
Across flats (s): 17mm
Across points (e): 18.72mm
Thread length: See diagram for indication. Please call us for exact measurement of current stock as it varies by batch
Material: A4 (316) Stainless steel
Din standard: DIN 571

Click here to view the full sizing table

Technical line drawing of A4 stainless steel coach screws

Delivery Terms

Orders over £100 will qualify for free 2-3 working day delivery*. Orders under £100 will be subject to a carriage charge - please see below for our delivery options.

We offer a number of different nationwide* services. Please see below for our delivery options.

*Please note that orders to the Isle of Wight, the Isle of Man, the Scottish Isles, the Scottish Highlands, Northern Ireland and the Channel Isles will incur a carriage surcharge.

*Long items greater than or equal to 1.5M in length will be subject to a length surcharge of £12. This surcharge is per shipment, and not per item.

Orders placed before 15:00 with next working day/timed services, Saturday & Royal Mail Special Delivery services will be dispatched the same day (Monday to Friday). Orders placed with any of these services after 15:00 will not be dispatched until the next working day. Orders placed on Saturdays, Sundays or bank holidays will be dispatched on the next working day. Next working day means Monday - Friday, excluding bank holidays. Orders placed with any of the aforementioned services will not be delivered on a Saturday or Sunday. For Saturday deliveries, select 'Saturday Delivery' in the basket.

We aim to despatch all orders with standard services within 2 working days, as long as all of the items are in stock.

Delivery Services

We offer the following delivery services:

Royal Mail standard tracked (3-5 working days) £4.50^^
Royal Mail 24 tracked (1-3 working days) £5.95^^
R/Mail Special Delivery next working day by 1pm^ £14.99^^
R/Mail Special Delivery next working day by 9am^ £39.98^^
Standard courier 2-3 working days £6.98
Express 1-2 working working day^ £8.99
Next working day by 13:00^ £10.99
Next working day by 11:00^ £14.99
DPD Saturday delivery^ £9.98

^Orders placed before 15:00 with next working day/timed services, Saturday & Royal Mail Special Delivery services will be dispatched the same day (Monday to Friday). Orders placed after 15:00 will not be dispatched until the next working day. Orders placed on Saturdays, Sundays or bank holidays will be dispatched on the next working day. Next working day means Monday - Friday, excluding bank holidays. Orders placed with any of the aforementioned services will not be delivered on a Saturday or Sunday. For Saturday deliveries, select 'Saturday Delivery' in the basket.

^^Royal Mail services are only offered to basket weights up to and including 2 kilos only. The 1pm & 9am Special Delivery times are for UK mainland only and will vary for Northern Ireland, Highlands & Islands. Please view the Royal Mail website for full details.

Please note that orders to the Isle of Wight, the Isle of Man, the Scottish Isles, the Scottish Highlands, Northern Ireland and the Channel Isles will incur a carriage surcharge.

Long items greater than or equal to 1.5M in length will be subject to a length surcharge of £12. This surcharge is per shipment, and not per item.

Collection

All orders are available for collection from our stores. Collection orders will normally be ready within 2 hours of the order being placed, as long as all items are in stock at the time of order.

Van Delivery

TC Fixings offers a free van delivery service to Saffron Walden and the surrounding villages.