5 New Watch Case Openers. Knife Case Opener. This is a new knife case opener. This unique tool makes opening cases easy. It is adjustable for opening any type of screw back watches. It measures approximately 6" (152 mm). Case Opening Knife. This is a new case opening knife. This universally popular shape gives the watchmaker a proper grip when prying open snap-on case backs. Hardwood handle and a precisely beveled, tempered steel blade makes case opening easier. It measures approximately 4 3/4" (121 mm). Bench Knife. This is a new bench knife. It works well for a wide variety of uses, especially scraping and prying. It has a wooden handle shaped to fit the hand. It measures approximately 6" (152 mm). Watch Opener Case Knife. This is a new watch opener knife. This is for snap-open backs. It measures approximately 4 1/2" (114 mm). Case Knife. This is a new case knife. Configured to make opening certain cases easier this opener is popular among many watchmakers. Simply place the blade under the case back and twist. It measures approximately 3" (76 mm).