IRWIN STRAIT-LINE Marking Chalk Refill: Black, Permanent, 5 lb

The IRWIN STRAIT-LINE Marking Chalk Refill: Black, Permanent, 5 lb (SKU: IRW-2032160) is the definitive choice for professional layout tasks that demand high-contrast, long-lasting lines in the most challenging outdoor environments. Formulated with a high concentration of black iron oxide, this permanent chalk provides an ultra-durable mark that remains visible for up to two months, even when exposed to direct sunlight, heavy rain, and consistent jobsite foot traffic. Unlike standard temporary chalks that wash away with the first storm, this IRWIN STRAIT-LINE refill is specifically engineered for permanence, making it an essential supply for long-term construction projects, foundational layouts, and industrial metal fabrication. Professional contractors and builders choose this 5 lb refill for its superior adhesion and visibility on diverse surfaces ranging from rough concrete to smooth steel. The fine-grind consistency ensures crisp, clean snaps with minimal clumping inside the reel, while the high-capacity container allows for multiple refills on large-scale commercial sites. Based in Lakeville, Minnesota, Fastener Express Inc. provides this industry-standard marking solution to crews across the 7-county Twin Cities metro, ensuring your team has the reliable supplies needed to keep layouts accurate and visible from groundbreaking to project completion.

• Maximum permanence formulation designed for exterior layout and harsh weather conditions.
• Weather-resistant pigment remains visible for up to 2 months of exposure to sun and rain.
• High-visibility black color provides superior contrast on concrete, wood, and light-colored substrates.
• Hi-Flow Nozzle Cap allows for faster, more precise chalk reel fills with reduced clogging.
• Airtight flip-top seal protects chalk from moisture to prevent clumping during storage.
• Industrial-grade consistency ensures crisp, sharp lines for high-accuracy snapped layouts.
• Tiered bulk pricing discounts available for 5+ and 20+ unit orders
• Same-day shipping on in-stock items ordered before 2 PM CST