The worker, who wished to remain anonymous, caught his wedding ring on part of the rotating shaft on a powered bowl mixer, which should have been guarded, Swindon Magistrates’ Court was told.
The man’s finger required partial amputation after the accident at the bakery’s Devizes premises on 3 March last year.
An investigation by the Health and Safety Executive (HSE) found that the company had modified the machine by adding a securing clip to a rotating shaft, but it hadn’t identified or addressed the additional risk created by the modification.
Haydens pleaded guilty to breaching Regulation 11(1) of the Provision and Use of Work Equipment Regulations 1998 and Regulation 3(3) of the Management of Health and Safety at Work Regulations 1999.
The business was fined £40,000, with costs of £5,950.
Last month, Haydens presented Wiltshire Air Ambulance (WAA) with a cheque for £1,034.