Description

The IRWIN INDUSTRIAL TOOL CO 4935520 is a 6-ounce fill of Midnight Black permanent staining marking chalk formulated for chalk reels used in layout and line-snapping applications on the jobsite. The chalk is designed to produce highly visible, long-lasting lines on a range of surfaces. Unlike standard chalk, the permanent staining formula resists wash-off, making it the right choice when layout lines need to stay put through multiple trades or weather exposure. Carpenters, framers, concrete workers, and general contractors reach for this product when temporary lines will not do.

This chalk is appropriate for residential and commercial construction layout, concrete slab and deck marking, roofing layout, flooring installation, and any application where a chalk reel is used to snap reference lines. The permanent staining formula is particularly useful outdoors or in high-traffic areas where standard chalk would smear or disappear before the work is complete. Sold in a package of 6 units.

Key Features

Midnight Black permanent staining formula holds up against smearing and moisture exposure
6-ounce fill size compatible with standard chalk reel fill openings
High-visibility black color improves line contrast on light-colored surfaces such as concrete and OSB
Packaged in a quantity of 6 for job-site stock or resale
Formulated for use with IRWIN STRAIT-LINE chalk reels and compatible equipment

Compatibility

Designed for use with chalk reels that accept standard powdered marking chalk, including IRWIN STRAIT-LINE chalk reel models. Suitable for any chalk reel with a standard fill opening.

Installation Notes

Fill the chalk reel with the cap or fill port fully open and avoid overfilling to prevent clogging the line exit point. When using permanent staining chalk, protect surrounding surfaces and finished materials from unintended contact, as the formula is difficult to remove. Wear appropriate PPE including eye protection when handling chalk powder in windy conditions. Dispose of empty containers in accordance with local regulations.