See paragraphs (a) and (e) of § 301.6323(h)-1 for definitions of the terms "security interest" and "tax lien filing." For purposes of this section, a judgment lien is a lien held by a judgment lien creditor as defined in paragraph (g) of § 301.6323(h)-1 .
For example, a surety company which holds a security interest, arising from cash disbursements made after tax lien filing under a payment or performance bond on a real estate construction project, has priority over the tax lien with respect to the proceeds of the construction contract and, in addition, with respect to any tangible personal property used by the taxpayer in the construction project if its security interest in the tangible personal property is protected under local law against a judgment lien arising, as of the time the tax lien was filed, out of an unsecured obligation.
26 C.F.R. §301.6323(c)-3