{"product_id":"castair-replacement-motor-pulley-hub-shaft-3-55-od-2b-grooves-p2b355h","title":"Castair Replacement Motor Pulley Hub Shaft 3.55\" OD. 2B Grooves P2B355H","description":"\u003ch2\u003eCast Air P2B355H — 3.55\" OD Dual-Groove B-Section Motor Pulley, Hub Mount\u003c\/h2\u003e\n\n\u003cp\u003eThe Cast Air P2B355H is a 3.55\" outside diameter motor pulley with two B-section belt grooves and a hub-mount bore configuration. Unlike fixed-bore pulleys, the P2B355H does not have a machined bore — it accepts a separate hub (ordered for your specific motor shaft size) that locks into the pulley and clamps onto the shaft. This design lets the same pulley body fit multiple shaft diameters depending on which hub you order. It is one step up in diameter from the P2B335-7\/8 in the Cast Air lineup, producing slightly higher pump speed from the same motor.\u003c\/p\u003e\n\n\u003cp\u003eHub pulleys are the right choice when: you need a diameter that is not available in a fixed-bore version for your shaft size, when you want the flexibility to reuse the pulley body if you change motors, or when the original equipment used a hub mount. For a 3.55\" dual B-groove motor pulley, the P2B355H paired with the appropriate hub is the Cast Air part for the job.\u003c\/p\u003e\n\n\u003ch3\u003ePulley Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e P2B355H\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 3.55\"\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBore Configuration:\u003c\/strong\u003e Hub mount (bore depends on hub selected)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Grooves:\u003c\/strong\u003e 2\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGroove Profile:\u003c\/strong\u003e B-section\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBelt compatibility:\u003c\/strong\u003e Two B-section V-belts (matched pair recommended)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Cast iron\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $38.50 (hub sold separately)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSelecting the Correct Hub\u003c\/h3\u003e\n\u003cp\u003eThe P2B355H requires a separately ordered hub. The hub matches your motor shaft size. Cast Air offers the following hubs:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX58:\u003c\/strong\u003e 5\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX78:\u003c\/strong\u003e 7\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX100:\u003c\/strong\u003e 1\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX118:\u003c\/strong\u003e 1-1\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX138:\u003c\/strong\u003e 1-3\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSD138:\u003c\/strong\u003e 1-3\/8\" shaft (SD taper-lock style)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSD158:\u003c\/strong\u003e 1-5\/8\" shaft (SD taper-lock style)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSK158:\u003c\/strong\u003e 1-5\/8\" shaft (SK taper-lock style)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSK178:\u003c\/strong\u003e 1-7\/8\" shaft (SK taper-lock style)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eMeasure your motor shaft diameter before ordering. The hub bore must match the shaft exactly. A hub that is 1\/8\" too large will not hold the pulley concentric with the shaft.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Hub-Mount Pulleys Exist\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlexibility:\u003c\/strong\u003e One pulley body, multiple shaft sizes — order the pulley once and pair it with the correct hub for whatever motor you have\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAvailability:\u003c\/strong\u003e Some OD\/shaft combinations are not practical to stock as fixed-bore pulleys. Hub mounts expand the available combinations significantly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReplaceability:\u003c\/strong\u003e If a hub wears or a keyway strips, you replace the hub, not the entire pulley — lower cost on the next service\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLarger shafts:\u003c\/strong\u003e Fixed-bore pulleys have practical bore size limits. For shafts larger than 1-3\/8\", hub mounts are typically the only option.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003ePump Speed at 3.55\" OD\u003c\/h3\u003e\n\u003cp\u003eThe 3.55\" OD is the second-smallest motor pulley in the Cast Air 2B lineup. As a reference point:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAt 1750 RPM motor speed with a 10\" pump pulley: pump runs at approximately 621 RPM\u003c\/li\u003e\n  \u003cli\u003eCompared to the 3.35\" P2B335-7\/8: the 3.55\" pulley increases pump speed by about 6%, slightly increasing CFM output and motor load\u003c\/li\u003e\n  \u003cli\u003eReplace with the same OD as the original unless you have a specific reason to change the drive ratio\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eDual B-Belt Drive Requirements\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUse matched belt pairs:\u003c\/strong\u003e When this pulley drives two B-belts, both belts must be replaced as a matched set. Mixing belt ages or brands creates uneven load distribution and accelerated wear on the tighter belt.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePump pulley must also be dual-groove:\u003c\/strong\u003e The 2B motor pulley pairs with a 2B pump pulley. If the pump pulley has only one groove, you cannot run two belts.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCheck belt tension on both belts independently:\u003c\/strong\u003e After installation, verify both belts are tensioned equally. An uneven drive creates lateral load on both the motor shaft and pump shaft bearings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e2B-Groove Hub Motor Pulley Lineup\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eP2B355H (this pulley):\u003c\/strong\u003e 3.55\" OD, hub mount — $38.50\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eP2B395H:\u003c\/strong\u003e 3.95\" OD, hub mount — $38.50\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eP2B445H:\u003c\/strong\u003e 4.45\" OD, hub mount (nearest official listing to P2B455H)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eP2B495H:\u003c\/strong\u003e 4.95\" OD, hub mount — $66.41\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e P2B355H\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 3.55\"\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBore:\u003c\/strong\u003e Hub mount (hub ordered separately)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Grooves:\u003c\/strong\u003e 2\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGroove Profile:\u003c\/strong\u003e B-section\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Cast iron\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $38.50 (hub not included)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cp\u003eHub-mount pulleys require getting two parts right: the pulley OD and the hub bore. We stock both the P2B355H and the full range of LX, SD, and SK hubs. When you call us, we will confirm both parts in one conversation and make sure you have everything you need to complete the installation without a second order.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e on qualifying orders\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFree tech support:\u003c\/strong\u003e Call 866-217-0063 — we will help you select the correct hub for your motor shaft size\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFull manufacturer warranty\u003c\/strong\u003e on all Cast Air parts\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHonest guidance:\u003c\/strong\u003e We will confirm both the pulley and hub before you order\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342573297877,"sku":"P2B355H","price":71.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/MOTOR-PULLEYS-300x248_214c8dee-d10b-42cf-8287-88a18e7d2404.jpg?v=1772652764","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-replacement-motor-pulley-hub-shaft-3-55-od-2b-grooves-p2b355h","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}