S.C. Code Ann. § 34-30-1650

The pledge or hypothecation to a state savings bank of all or part of a savings account in joint tenancy by any tenant or tenants, whether minor or adult, upon whose signature or signatures withdrawals may be made from the account is, unless the terms of the savings account provide specifically to the contrary, a valid pledge and transfer to the state savings bank of that part of the account pledged or hypothecated, and does not operate to sever or terminate the joint and survivorship ownership of all or part of the account.