Transferable Skills. Grids. Court remanded where ALJ relied on Grid rule requiring transferrable skills but failed to find explicitly (or to indicate the basis for his implicit finding) that 55-year old claimant's skills were transferable. The claimant has the burden of showing disability serious enough to prevent him from working at his former jobs. The burden then shifts to the Secretary to show the existence of other jobs in the national economy that the claimant can nonetheless perform.