Check the replacement line specification ID: lst300-line-spec Version: 2.0.0 Model: BLACK+DECKER LST300 · US · AF-100 Region: US Parts: Automatic-feed head with AF-100 spool; match model and tool type to manual Not covered: LST420 / LSTE525; GH corded models; Dual-line heads; Metal line or blades; Nonmatching tool type or modified head; Unknown tool type or missing exact-type manual; Bump-feed conversion MATCH YOUR VERSION Model and tool type: LST300 and the exact type on my label match my manufacturer manual and figures Remove the battery before finding the label. Use the manufacturer model-and-type lookup; this site does not infer a type number from LST300 alone. Cutting head: Original AF-100 automatic-feed single-line head Do not substitute a bump-feed procedure, dual-line spool or metal cutting attachment. PREPARE [ ] Release the trigger, let the head stop, engage the lock-off and remove the battery. Leave it removed throughout hands-on care. Keep fingers away from the sharp cutter on the guard. [ ] Read LST300 and the tool type from the label. Open the official model/type lookup and compare its manual and parts figures with your actual guard, single-line head and AF-100 spool. A readable model name alone does not establish the type. If the exact type manual cannot be obtained, or any figure differs, save a preparation record and stop. [ ] Tool: Good lighting [ ] Material: No replacement material needed for an intact tool STOP Keep the battery removed if the exact type/manual match is unknown or parts differ from the figures. Stop for a damaged battery, exposed wiring, a faulty switch, cracked guard, broken spool/hub, damaged cap tabs or housing slots. Use an authorized service center. Never open the battery, motor housing or charger. CONSUMABLE FIT Factory-wound replacement spool: BLACK+DECKER AF-100; 0.065 inch (1.65 mm) round nylon monofilament Fit: Original LST300 automatic single-line head, after exact tool-type/manual match Do not substitute: Bump-feed or dual-line heads; metal, serrated or heavier line; unverified replacement heads Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories Bulk cutting line: 0.065 inch (1.65 mm) round nylon monofilament Fit: Intact original AF-100 spool with the slot, adjacent anchor hole, arrow and fill recesses in figs P–R Do not substitute: Serrated, square, heavier or metal line; different anchor geometry Source: lst300-manual, English p10 Rewinding spool from bulk line; figs P–R Replacement spool cap: BLACK+DECKER RC-100, confirmed against the exact tool-type parts list Fit: Original compatible AF-100 housing with undamaged slots Do not substitute: Damaged housing; caps with different tabs; forcing an apparently similar part Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories CHECK ROUTE safety: Is the battery removed, the trigger released and the cutting head stopped, with no battery damage, exposed wiring or faulty switch? Yes -> compatibility: Keep the battery removed for every hands-on step. No -> service: Stop using the tool for electrical, battery or switch damage. If you have only omitted battery removal, make the tool safe before restarting. Not sure -> prepared: Keep the battery removed. Save your preparation record and check the matching manual before continuing. compatibility: Have you matched the label LST300 AND its exact tool type to the official lookup manual and its figures, with the original AF-100 automatic single-line head? Yes -> check-1: Record the label type and matching manual reference in the first step. No -> prepared: An unknown type, unavailable type manual, different figures, bump-feed head or dual-line conversion blocks this procedure. Use manufacturer support to identify the correct instructions. Not sure -> prepared: Keep the battery removed. Save your preparation record and check the matching manual before continuing. check-1: Can you read the actual spool or line package and identify its diameter, shape and material? Yes -> check-2: Read every specification; color alone does not establish compatibility. No -> prepared: Obtain a readable label or manufacturer part listing before fitting it. Not sure -> prepared: Keep the battery removed. Save your preparation record and check the matching manual before continuing. check-2: Does it specify AF-100 or 0.065 inch (1.65 mm) round nylon monofilament for the matching original head? Yes -> steps: Record the part details and choose a fitting method. No -> prepared: Set aside serrated, heavier, metal or otherwise unverified line and obtain the correct specification. Not sure -> prepared: Keep the battery removed. Save your preparation record and check the matching manual before continuing. CARE STEPS (only when the route reaches steps) [ ] 1. Record the exact tool and make it safe Release the trigger, let the head stop, engage the lock-off and remove the battery. Leave it removed throughout hands-on care. Keep fingers away from the sharp cutter on the guard. Read LST300 and the tool type from the label. Open the official model/type lookup and compare its manual and parts figures with your actual guard, single-line head and AF-100 spool. A readable model name alone does not establish the type. If the exact type manual cannot be obtained, or any figure differs, save a preparation record and stop. Look for: The battery is physically separate from the tool; your label type and matching manual reference are written below. Source: bd-manual-help, Official model/type lookup instructions; type is beside or below the model number [ ] 2. Read the replacement label Read the actual package, not just a listing photo. For a factory-wound spool, check BLACK+DECKER AF-100. For loose line, check 0.065 inch (1.65 mm), round cross-section and nylon monofilament. Look for: All required markings are readable and refer to the part you have. Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories [ ] 3. Exclude incompatible cutting material Set aside heavier or serrated line, metal cutting material and a spool intended for a dual-line or bump-feed head. Do not substitute a different line because it fits through the eyelet. Look for: The selected line matches diameter, shape and material together. Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories [ ] 4. Check the cap separately If a cap is required, the manual lists RC-100. Match it to the exact tool-type listing and original housing, including both tabs. A correct cap does not make a damaged housing usable. Look for: The cap marking and retention design match; no damaged tabs are being reused. Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories [ ] 5. Choose factory-wound or hand-wound line The manufacturer recommends factory-wound spools for best results and notes that hand-wound line can tangle more often. Choose the spool-replacement task for AF-100, or the model-specific rewind task for an intact original spool and compatible bulk line. Look for: Your choice leads to the appropriate installation sequence rather than mixing their anchor steps. Source: lst300-manual, English p10 Rewinding spool from bulk line; figs P–R [ ] 6. Save the compatibility decision Record the markings and whether the part passed. Keep any incompatible part separate and leave the head closed until the correct material is ready. This task confirms supplies; fitting and a normal-use check are separate tasks. Look for: The record identifies the actual consumable and the next fitting task. Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories OBSERVATIONS Tool type exactly as printed on the label (required): ____________________ Exact-type manual reference or link that you matched (required): ____________________ Diameter, shape, material and spool marking checked (required): ____________________ Chosen fitting route (required): ____________________ Choices: Factory-wound AF-100 replacement / Rewind the original spool with compatible bulk line / Part still unverified; leave the tool unused [further care/preparation needed] Result of this task (required): ____________________ Choices: Checks passed; ready for the stated next step / More preparation or a linked task is needed [further care/preparation needed] / Leave unused and contact service [service required] RESULT CHECKS [ ] Spool or loose line is positively identified as the specified round nylon consumable. [ ] Any required cap matches RC-100 and the exact tool-type parts listing. NEXT CARE Before buying or fitting cutting line, a spool or cap Inspect when the stated condition occurs. The manual gives no fixed day or month interval. Basis: manufacturer Source: lst300-manual, English p9 Cutting line / Line feeding; Replacement accessories Record preparation, maintenance readiness, problem located or service needed. This is not proof of a physical repair. SOURCES BLACK+DECKER LST300 instruction manual (manufacturer document, retailer-hosted) https://pdf.lowes.com/productdocuments/1935f26b-7448-4c95-b467-a223bb73d80f/63056925.pdf English p9 Cutting line / Line feeding; Replacement accessories Checked: 2026-10-13 Manufacturer copyright, hosted by Lowe’s. Facts paraphrased; no diagrams or manual redistributed. BLACK+DECKER: locate a manual using model and type number https://support.blackanddecker.com/hc/en-us/articles/360012700118-How-can-I-get-a-parts-list-or-manual-for-my-tool Official model/type lookup instructions; type is beside or below the model number Checked: 2026-10-13 Linked only. BLACK+DECKER LST300 product and support https://www.blackanddecker.com/products/lst300 LST300 model identity; Automatic Feed Spool; Includes AF-100 Checked: 2026-10-13 Linked only; no product photos reused.