Giftware products combining pewter (Sn5Sb1.2Cu) and glass require good matching up for strong adhesive bonding. The possibility of joining the parts without good matching using ultrasonic soldering is commercially attractive. Ultrasonic soldering was applied to bond the two substrates using (Sn40Bi)0.5Al as solder alloy at temperature not exceeding 450 °C. All parameters were kept constant except for the glass surface roughness. Analyses were conducted on the effects of glass surface roughness on shear separation force and extension before fracture of solder joint. The separation force and extension before fracture were determined by subjecting the soldered specimen to tensile stress test. Effect on shear separation energy was derived by calculation. Separation energy of joint between glass and Sn5Sb1.2Cu based on ultrasonic soldering can be strengthened by increasing glass surface roughness.