Liam Benson was one of three hooded raiders who battered their way through locked doors and then smashed up display cabinets at The Gold Shop on Wakefield Road, Dudley Hill.
The late morning robbery on May 23 was captured on the shop’s CCTV cameras, Bradford Crown Court heard.
The trio, armed with a baseball bat, machete and a sledgehammer, spent just over two minutes “scooping up” over £100,000 worth of rings, pendants and watches.
Shop owner Maurice Willan, two work colleagues and a male customer had all retreated to a secure room at the rear of the premises as the intruders smashed their way in.
Mr Willan switched on the automatic roller shutter doors, trapping the gang but they soon escaped by forcing the shutters.
None of the stolen jewellery has been recovered.
Benson, who previously served a jail prison sentence for an aggravated burglary at a 92-year-old woman’s home, was linked to the raid by a palm print on a cabinet in the shop.
Benson, of Third Avenue, Rothwell, admitted the robbery charge.
He claimed to have only become involved on the day of the raid and was being pressured over a cannabis debt.
Judge Durham Hall said the offence had been a professionally planned and targeted commercial robbery.
He said the degree of force used to smash open the locked door had caused those inside to flee in terror.
“This was indeed a professionally planned commercial robbery by a gang who displayed not only great strength and ferocity but also a degree of coolness.
“The robbery was carried out from start to finish in about two and a half minutes and that was the time needed to remove that family business of over £100,000 worth of property.”
Two other men involved in the robbery have never been traced.