FAQ

FREQUENTLY ASKED QUESTIONS

CONNECTION IN 20 GAUGE STEEL

QUESTION: Do I use your Marker® (sharp points) or your Darts® (self-drilling) points to attach 20 gauge stud to track?

ANSWER: The Darts® Brand self-drilling screw is the recommended fastener for two pieces of 20 gauge steel. Sharp point screws are designed to pierce the steel and when try to attach two pieces you will pierce the first and possibly deform the second piece by pushing away the material before the connection is made.

CORROSION

QUESTION: Would attaching wood to aluminum beam with a Lifecoat® plated screw create any problem with corrosion or galvanic reaction?

ANSWER: Lifecoat®, is a nonconductive organic coating (Epoxy) with very solid adhesion. Even after driving through wood, thin steel or aluminum, the coating will still bonded tightly with the screws. The organic coating itself is a nonconducting layer thus, no Galvanic reaction will occur unless the coating was damaged due to improper installation when the screw was driven into the wood or metal plate. If damaged, no plating can stop the spreading of rust from the wound.

DECKING SCREWS

QUESTION: I am building an outdoor deck and want to know if the gold drywall screws are the best for this application.

ANSWER: The gold or yellow zinc coated screws are not recommended for outdoor applications. Our Marker® Decking screw line includes the following choices for all outdoor applications:
Dacro - is the most cost effective and exceeds a 300 hours salt spray test.
Plus Coat - is a ceramic coating that exceeds a 500 hours salt spray test.
Lifecoat® - is our premium coating that exceeds 2000 hours salt spray test.

DECKING SCREWS - "CUT OUT POINT" TYPE 17 POINT

QUESTION: I have seen many decking screws with a "cut out" on the sharp point that claims to work better in wood. Why don’t your decking screws have this type of point?

ANSWER: Most outdoor decks are constructed using some type of softwood. The type 17 point will cut out or disturb too much of this softwood resulting in decreased pullout value or even stripping. Our Square drive Lifecoat® was designed for applications of soft and hard woods. The positive Square drive and our AT® thread design assure a good connection even in hardwoods. Our Marker® Dacro or Plus Coat decking screws are the most cost effective fasteners for all softwood decking applications.

DRILL POINTS "BURNING"

QUESTION: In attaching gypsum board to 18 gauge steel studs, I am using the bugle head self-drilling drywall screw, but I am burning off the drill tips. I am using my regular drywall tool with 4,000 RPM. What screw should I use for 18 gauge?

ANSWER: You are using the correct fastener but the wrong tool. The self-drilling point burns up because the RPM is too fast. You need to slow down enough to allow the drill point to drill through the material. The correct tool for use with steel is 2500 RPM maximum for #6, #8, and #10 body diameter screws; 1800 RPM maximum for #12 and #1/4 body diameters.

DRILL POINT SIZES

QUESTION: We have a job that specified a number 3 self-drilling point. What does that mean?

ANSWER: The number three designates the drilling capacity of the self-drilling fastener. You can have a number 1, 2, 3, 4 or 5 point self-drilling point call-out. The larger the number the thicker material the screw is designed to drill. The number 1 point is for very light steel and the number 5 is designed to drill up to 1/2" thick steel. The manufacturer should provide a list of the body diameters available with each point style. They should also provide a drill capacity chart showing the application thickness of their self-drilling fasteners.

Basic rule of thumb would be: If the flute of the self-drilling point is longer than the total thickness of the connection (including any space between them), the screw will work correctly (See the figure below).

POINTS.jpg (13390 bytes)

FIBER CEMENT BOARD PRODUCTS

QUESTION: What is the best fastener for attaching fiber cement board to 26 gauge steel?

ANSWER: We will assume this is a 26 gauge steel stud in a non load-bearing wall. There is no fastener for this application.

The fiber cement board is an extremely dense material and very heavy in comparison to gypsum boards. The 26-gauge steel is so thin that no fastener can install the fiber cement board without stripping the connection. The failure occurs when the steel deforms causing the screw to pull out. Fiber cement board manufacturers recommend a minimum of a 20 gauge steel stud.

K-LATH HEAD DESIGN

QUESTION: What is the actual diameter of your K-lath/Modified truss screw? Are all brands the same?

ANSWER: Marker® and Darts® brand Modified Truss (K-lath) head designs have an approximate 7/16" outside diameter of the head.

Marker® and Darts® brand Modified Truss (K-lath) head designs conform to ASTM C954 and ASTM C1002 criteria for the fastening of metal plaster bases to steel or wood. This specification lists a minimum head OD of .437", as noted in Section 5.2.3.1 of ASTM C954.

All brands are not the same and do not meet this minimum head diameter requirement or the performance requirements of these specifications. Your supplier should provide certification showing ASTM compliance.

THE QUADREX® DRIVE SYSTEM

QUESTION: Your brochure shows the Quadrex® drive as a combination of the square drive and the Phillips drive. Can I use either bit tips to drive this screw?

ANSWER: No. This unique Quadrex® drive system works from 8 driving points within the recess of the screw head. With such a positive drive, it is not necessary to have such a deep recess in the screw head. Since less material is removed from the head of the screw, its strength is increased.

The Phillips drive works off of the recess depth, it will not work properly in the Quadrex® drive. It will just spin.

The #2 square drive will be able to install the screw, but the Quadrex® bit tip is always the recommended bit tip.

SHARP POINTS

QUESTION: Does a drywall screw have a type "A" point?

ANSWER: No. The typical drywall screw has a "needle point". The generic term for this type of point is "self-piercing". The type "A" tapping screw has a point angle of 45 degrees; while self-piercing point typically ranges from 23 to 30 degrees.

YELLOW ZINC VS. BLACK OR GRAY PHOSPHATE COATINGS

QUESTION: Is it true that yellow (gold) zinc plating makes screws harder and stronger than the black or gray phosphate?

ANSWER: No. It may seem as though the gold or yellow zinc plating makes the screw harder or stronger but the difference is only the plating itself. The phosphate plating is a very abrasive plating that creates more torque as the screw is being driven and may cause breaking if the correct diameter fastener is not used. The yellow zinc (gold) has a slick plating surface with enough lubricity to help reduce the torque created as the screw is being driven, therefore creating the illusion of more strength. This plating actually reduces torque allowing the screw to be driven more easily in a tough application.