History The original A5 Clipper & A5 Blade were patented and manufactured by John Oster, a Swedish immigrant to the USA, in 1960 (US2928171A) and are similar to an earlier 1939 John Oster design (US2182597A). By the mid 1980's Oster, Andis and Moser all made popular clippers which took A5 blades and sold A5 clipper blades to go with them. Nowadays A5 blades are the standard snap on clipper blade and most brands sell A5 type clippers and blades to go with them. A newer version of John Oster's original 1960's A5 clipper can still be bought today and most the components are compatible with the original 1960's version. Design A5 blades are a type of clipper blade which "snap off" your clipper in one piece without unscrewing them so you can easily remove blades and swap them to any A5 compatible clipper. A5 blades have a bracket on the back which has 2 small "wings" at the sides of a central a backplate. A5 compatible clippers have a spike on a hinged bracket which the A5 blade slots onto and rotates back onto the clipper head. On A5 animal grooming clippers the A5 blade locks into place with a small latch mechanism. Cutting Lengths - Dog grooming A5 clipper blades have a range of cutting lengths numbered: #50 cuts 0.1mm, #40 cuts 0.25mm, #30 cuts 0.5mm, #15 cuts 1mm, #10 cuts 1.5mm, #7 cuts 3mm, #5 cuts 6mm, #4 cuts #12mm, #3 cuts 16mm and 3/4" cuts 19mm. - Barbers & hair dressing A5 clipper blades are numbered differently: #00000 (0.1mm), #0000 (0.25mm), #000 (0.5mm), #0A (1.2mm), #1 (2.4mm), #1A (3.2mm), #1 1/2 (4mm), #2 (6.3mm), #3 1/2 (9.5mm), #3 3/4 (13mm) Cutting Width - Standard A5 blades the cutting teeth are around 45mm wide - Narrow "Toe" A5 blades are around 15mm wide - Wide A5 blades are wider than normal and around 65mm wide. Ceramic A5 Blades Ceramic A5 Blades are normal A5 blades with a Ceramic cutter part fitted. Ceramic cutters are supposed to stay sharp for longer and heat up less during use. We can fit a new ceramic cutter to your normal width A5 blades as part of clipper blade sharpening and this costs £2 extra. See: Ceramic Clipper Blade Sharpening. Ceramic cutters are only for normal width A5 blades and not the narrow toe blades or wide A5 blades. The picture below shows the back of a A5 Toe Clipper Blade and you can see the 2 wings on the sides of the central bracket which sits in the middle of the wider tension spring.