Kevlar is a synthetic fibre that can be spun into fabric five times stronger than steel and is used in armoured vests worn by British troops in Iraq.
The uniforms, which cost 311 dollars, have been developed in the midst of growing concern about the number of teenagers who have been stabbed to death, including the killing of promising footballer Kiyan Prince who was attacked only meters away from his school gates in north London.
Barry Samms, one of the firm's directors, said the company originally produced stab-proof hooded tops that were bought by teenagers. But eventually they were asked by parents about the likelihood of strengthening school uniforms with Kevlar.
"The blazers and jumpers have come on the back of the hooded tops which we launched in April. Since then we had a small amount parents contacting us and asking if we could do something similar with their kids' uniforms so we have been modifying them for them," the Daily Mail quoted Samms, as saying.
Samms added that parents who had sought inquiry about stab-proof clothing were genuinely worried for their children's safety.
"From what I can gather and from speaking to parents it's just peace of mind for them. I spoke to a lady yesterday whose son was mugged on a bus coming home from school. She has also got two daughters, but she always sends them to school with no money on them and no jewellery," he said.
However, despite seven boys under the age of 16 dying in UK knife attacks in a period of just two months this year, police chiefs have branded the precautions as an "extraordinary step".
"The reality of course is that crimes involving knives are proportionately very very low," Alf Hitchcock, of the Association of Chief Police Officers told BBC News Online.