Unlucky Jason Merritt was then trapped in the heavy machinery, with his left arm still attached to the saw with just millimetres of skin and nerves.
The security officer, who was chopping up an old shed for fuel for the wood burner, said it all happened so fast that he still not sure what caused it.
He said: “All of a sudden there was some kind of pulling in and then I could see my hand had come away from my arm.
“I was just looking at my hand on the table and my heart plummeted, and I just thought, ‘Oh Christ’.”
The brave step-grandad, who celebrates his 50th birthday today (Friday) was in his garden when the accident happened on Friday, November 13.
Jason, who lives in Farsley, was stuck, so the only thing he could do was to shout: “Help, help, help!”
A local resident, who lived behind Jason’s house and was unknown to him, came jumping over a neighbour’s shed and into his garden to come to his rescue.
The man saw to Jason and rang Jason's wife, radiographer Elaine, 64, on her mobile and told her what had happened and kept the pair calm.
An unknown person dialled 999 at around 2.30pm and amazingly, all the emergency services, including the Yorkshire Air Ambulance arrived at their home in Merton Gardens within minutes.
The rest is unknown to Jason as he was administered heavy pain relief to knock him out so he could be freed from the machinery in an hour-long delicate operation.
All the while, police were knocking on the doors of neighbours to ask for ice to pack his hand in.
He was then rushed to Leeds General Infirmary where the specialist Hand Surgery and Rehabilitation team were able to reattach his hand in a complex eight-hour procedure.
Jason has lost 2cm from his arm where it had to be cut to create a smooth surface for reattachment.
It was then plated back together at the dedicated unit, with the surgeon performing intricate work to reattach nerves, muscles, tendons, arteries and veins.
It was then stitched back together.
Jason spent four days on the High Dependency Unit and a further two days on a ward.
Although Elaine couldn’t visit him in hospital the pair kept in touch through WhatsApp, speaking to each other constantly, which was a relief for Elaine.
He was sent home on November 19.
Wife and mum-of-two, Elaine, said: “I had to rush from my work at the Spire Hospital, Leeds, but Jason wasn’t at home when I got back.
“He’d already been airlifted to hospital. Of course, I couldn’t go to hospital.
“My son rushed over to see me, and he looked outside to see the aftermath, I could not face it.
“He told me the amount of blood there was surprisingly less than he thought there would be, in fact everybody has said that.
“We suspect that Jason having been trapped to the machinery must have stemmed some of the blood flow.”
The mitre saw that Jason was using was an old Challenge model, inherited from his dad.
His dad was handy around the house and so too was Jason.
Jason always did his own home renovations and helped family with theirs, he was good at any joinery work and had even fitted kitchens and bathrooms.
He had used the mitre saw countless times before and has never had an accident like this.
Jason said: “I was wearing a hoodie, so I think maybe that had been caught in it somehow, but I just don’t know really.
“It all happened so fast.”
But Elaine said: “It is in the garage now, but it will be going to the tip. We will not be using that again.”
Jason is now recovering at home, doing his best with the use of one hand.
His arm is in a pot so that it stays in the one position to help recovery, he cannot use his left arm at all.
Jason said: “I’m expecting I’ll be kicked out of the kitchen this Christmas, I’ll just get in the way.”
Every few days he has the dressing changed and it is then he gets to see the damage.
Jason says it still hurts but he is only on paracetamol and ibuprofen for the pain.
It is numb to touch.
Medics have told him it will take 18 months to two years for the nerves to grow back.
Now the pair are wanting to thank all of those who were involved in saving Jason.
Jason said: “I will be forever grateful to all of those who took part in saving me, from the guy who jumped over the fence, to all the emergency services who worked efficiently and speedily to save me.
“I dread to think what could have happened if nobody had heard me. I could be here without a hand, or it could be even worse.
“Even now we still don’t know who actually rang 999 to get the emergency services to me.
“I would love to be able to find them so I can thank them. I am so grateful for all my care.
“We also feel humbled by the kindness and support shown to us by our family, friends and colleagues. Everybody has been amazing.”