Police said the culprit also threw a chair at a staff member before fleeing the Park Street shop with jewellery last month.
The raid happened at 4.30pm on September 27 as the force released CCTV images of the culprits in a bid to track them down.
A spokesman for Walsall Police said: "We appreciate these images don't give a clear view of the suspect who spoke with a local accent, but we believe people out there will know who was involved.
"We're keen to hear from anyone who was in and around the Park Street area at the time and may have important information."
Contact the force via live chat at west-midlands.police.uk or by calling 101. Quote 20/1766837/21.