RS PRO M3 x 6mm Zinc Plated Steel Pan Head Sems Screw, Plain Washer

  • RS stock no. 278-821
  • Manufacturer RS PRO
Technical data sheets
Legislation and Compliance
COO (Country of Origin): CN
Product Details

RS PRO SEMS Screw with Plain Washer

From the trusted RS PRO brand, these pan head SEMS screws are ideal for when a good speed of assembly is required. SEMS screws have advantages over similar threaded screws in that a loose washer is pre-fitted to the fastener, saving you time in selecting and fitting a separate washer. As such, whenever a quick installation is required, these SEMS screws are ideal.

The screws feature a bright zinc finish which provides an element of corrosion resistance which makes them ideal for use in most indoor environments. They also feature a pozidriv head for maximum torque in installation.

Available in the following sizes;

278-821 is an M3 x 6mm SEMS screw 278-837 is an M3 x 12mm SEMS screw
278-865 is an M4 x 6mm SEMS screw
278-871 is an M4 x 12mm SEMS screw
278-916 is an M5 x 10mm SEMS screw
278-922 is an M5 x 16mm SEMS screw
278-950 is an M6 x 12mm SEMS screw
278-966 is an M6 x 16mm SEMS screw
278-972 is an M6 x 20mm SEMS screw

Features and Benefits

Screw with pozidriv head Plain washer
Easier and quicker to install than separate screws and washers
Bright Zinc Finish


Used wherever conventional screw fasteners are needed, SEMS screws are ideal for optimized work environments due to being a pre-assembled washer and screw combination. They are designed with convenience in mind, saving you time and effort in installation. They might commonly be used in;

• Production environments
• Maintenance
• DIY Applications

What does SEM mean?

In this case, SEM is simply a shorthand way of saying 'pre-assembled.'

What is the advantage of a Pozidriv screw?

A Pozidriv screw is an improvement on the crosshead screw, or Phillips screw. Like the crosshead, the Pozidriv screw naturally centers the torque when a Pozidrive screwdriver is applied, meaning there is less resistance and more control when screwing and unscrewing. To lessen the chance of the driver slipping from the screw head, known as cam out, the Pozidriv screw is preferable even to the Phillips screw.


RS PRO aims to be your go-to brand for reliability and value for money. We source great parts at great prices and test everything with our in-house experts to ensure the quality you need.

When it comes to tools, we know that versatility and dependability are what you need. As such, we stock a variety of mainstay and specialist tools to suit any application. Whether you're a professional electrician, plumber, builder or DIY enthusiast, RS PRO is here to support you.


The screw measures 6 mm long and has M3 threading for a tight fastening.

Attribute Value
Length 6mm
Thread Size M3
Head Shape Pan
Drive Type Pozidriv
Washer Type Plain
Material Steel
Finish Bright Zinc Plated
25 Available for same day despatch or collection. (Delivery Terms & Conditions Apply)
382 Available in 4–6 working days for collection or delivery to major cities, unless heavy, bulky, hazardous or lithium metal (T&C’s Apply)
Price (Excl VAT) 1 Bag of 100
R 86.65
(exc. VAT)
R 99.65
(inc. VAT)
Per Bag
Per unit*
1 - 4
R 86.65
R 0.866
5 - 9
R 84.48
R 0.845
10 - 29
R 81.95
R 0.82
30 +
R 78.67
R 0.787
*price indicative