{"product_id":"master-lock-pro-series-4-hidden-shackle-padlocks-keyed-alike","title":"Master Lock Pro Series (4) Hidden Shackle Padlocks Keyed Alike","description":"\u003cp\u003eIn this review the Master Lock Pro Series 6271KA-4 is evaluated as a heavy-duty keyed alike padlock pack for commercial and industrial use. The bottom line is simple: if you need four identical, high-security padlocks with concealed shackles to protect trailers, vending, or outdoor equipment, this pack delivers robust physical security and convenience with eight keys included. The review highlights fitment considerations and real-world durability so buyers know when these locks are an appropriate choice.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHidden shackle design:\u003c\/strong\u003e The lock body conceals the 3\/8 in hardened boron alloy shackle, reducing leverage points and improving resistance to cutting and prying.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKeyed alike convenience:\u003c\/strong\u003e All four padlocks open with the same key, allowing a single key to manage multiple locks and simplifying access for teams.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy duty construction:\u003c\/strong\u003e The reinforced 2-7\/8 in zinc die-cast body provides rugged protection against outdoor conditions and impact.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePick resistant cylinder:\u003c\/strong\u003e A re-keyable 6-pin cylinder with spool pins raises the difficulty of picking while remaining serviceable for rekeying if needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClear fitment guidance:\u003c\/strong\u003e The product includes dimensional guidance for hasp fit and a schematic so buyers can check that the shackle will engage their latch.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLifetime guarantee:\u003c\/strong\u003e The manufacturer backs the lock with a lifetime guarantee, offering long-term confidence in the purchase.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThese padlocks suit fleet operators, contractors, and owners of cargo trailers or vending equipment who require multiple locks that share one key and need protection against bolt cutters and casual theft. The concealed shackle and hardened boron alloy make them a solid choice where exposed shackles would be vulnerable.\u003c\/p\u003e\n\u003cp\u003eShoppers who have unusual or oversized hasps should check the provided schematic and measure the center distance and hole depth before buying; some enclosed trailer latches may be off-center and prevent the pin from engaging. If you need locks guaranteed to be keyed alike across multiple separate multi-packs, order the single 8-pack option rather than two 4-packs.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eExcellent physical security thanks to a fully shielded shackle and hardened boron alloy construction.\u003c\/li\u003e\n\u003cli\u003eConvenient keyed alike setup with two keys per lock, totaling eight keys for the pack.\u003c\/li\u003e\n\u003cli\u003eSolid build quality and good value for buyers needing multiple heavy-duty locks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot guaranteed to be keyed the same if you order two separate 4-packs, so larger orders require the 8-pack for consistent keying.\u003c\/li\u003e\n\u003cli\u003eMay not fit all trailer hasps; requires measuring hasp hole center and depth to confirm fitment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003ePack quantity\u003c\/td\u003e\n\u003ctd\u003e4 padlocks, keyed alike\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKeys included\u003c\/td\u003e\n\u003ctd\u003e8 total keys (2 per lock)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBody width\u003c\/td\u003e\n\u003ctd\u003e2-7\/8 in (73mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShackle diameter\u003c\/td\u003e\n\u003ctd\u003e3\/8 in (9mm) hardened boron alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShackle dimensions\u003c\/td\u003e\n\u003ctd\u003eA 3\/8 in (9mm) B 19\/32 in (15mm) C 1-23\/32 in (44mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCylinder\u003c\/td\u003e\n\u003ctd\u003eRe-keyable 6-pin with spool pins\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eLifetime guarantee\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Master Lock Pro Series 6271KA-4 is a practical, heavy-duty choice for anyone needing multiple keyed alike padlocks with concealed shackles and strong resistance to cutting and prying. It represents good value for commercial and outdoor use, provided buyers verify hasp fitment and order the correct pack size when identical keying across many locks is required.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWill two separate 4-packs be keyed the same?\u003c\/strong\u003e\u003cbr\u003eNot necessarily; if you need eight locks keyed the same, purchase the 8-pack option to ensure identical keying.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I check fitment for my trailer latch?\u003c\/strong\u003e\u003cbr\u003eMeasure the hasp\/latch hole center distance and depth against the provided schematic; if the hole center is more than 13\/16 in (20mm) from the edge the lock pin may not engage.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre these padlocks weather resistant?\u003c\/strong\u003e\u003cbr\u003eThe reinforced zinc die-cast body and concealed shackle offer strong outdoor durability and protection from cutting and prying for typical external applications.\u003c\/p\u003e","brand":"Master Lock","offers":[{"title":"Default Title","offer_id":48608727498971,"sku":"B01MF7LJSA","price":120.22,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/71B211NwLrL._AC_SL1146.jpg?v=1778384970","url":"https:\/\/gearmusthave.com\/products\/master-lock-pro-series-4-hidden-shackle-padlocks-keyed-alike","provider":"GearMustHave","version":"1.0","type":"link"}