HIDfast HF2.5 vs HF3 vs HF3M: Which Fastener Do You Need?
HIDfast fasteners are sold in four current models that differ by fastener length and the board spacing gap they create. This comparison uses only specifications verified in the current Fastener Express product records so you can choose the correct fastener without guessing.
The Four Current HIDfast Fastener Models
All four current models are 304 stainless steel, collated in strips, and intended for use with the HIDfast Decking Tool. They are sold in 175-count boxes. The differences are fastener length and the gap each fastener sets between boards.
Verified specifications from current product records
| Model | SKU | Length | Gap (board spacing) | Package | Material | Tool required | Price |
|---|---|---|---|---|---|---|---|
| HF2.5 | HF25-175 | 2-1/2" | 1/8" | 175 ct | 304 stainless | HIDfast Decking Tool | $105.95 |
| HF3 | HF3-175 | 3" | 1/8" | 175 ct | 304 stainless | HIDfast Decking Tool | $105.95 |
| HF3M | HF3M-175 | 3" | 3/16" | 175 ct | 304 stainless | HIDfast Decking Tool | $105.95 |
| HF3WG | HF3WG-175 | 3" | 1/4" | 175 ct | 304 stainless | HIDfast Decking Tool | $104.95 |
Fastener Length: 2-1/2" vs 3"
The HF2.5 is a 2-1/2" fastener; the HF3, HF3M and HF3WG are 3" fasteners. Longer fasteners provide more penetration into the joist, which suits thicker boards. The correct length depends on board thickness and the decking manufacturer's requirements — do not assume a length without confirming the board.
Gap: 1/8", 3/16" and 1/4"
The gap is the board-to-board spacing the fastener creates. HF2.5 and HF3 set a 1/8" gap; HF3M sets a 3/16" gap; HF3WG (wide gap) sets a 1/4" gap. The right gap depends on the decking product's required spacing for thermal expansion and drainage, which varies by material and manufacturer.
Board Thickness and Profile Considerations
Board thickness, profile (square-edge, single-groove or double-groove) and the decking manufacturer's instructions determine which model is appropriate. Pre-grooved boards also require the grooved-board attachment for the HIDfast tool. Because these factors vary by product, application depends on the specific board — verify before ordering.
Don't guess
Which Fastener for Which Application
| If your project calls for… | Consider |
|---|---|
| A 1/8" gap with a thinner board | HF2.5 (2-1/2") |
| A 1/8" gap with a thicker board | HF3 (3") |
| A 3/16" gap | HF3M (3") |
| A 1/4" (wide) gap | HF3WG (3") |
| Pre-grooved boards | Add the grooved-board attachment |
These pairings are starting points, not approvals for every board. Confirm against the decking manufacturer's current installation requirements.
Estimating Boxes
Each box holds a verified 175 fasteners. To plan how many boxes to order, use the HIDfast quantity estimator, then divide the estimated fastener count by 175 and round up.
Source Note
Length, gap, package count, material and price are taken directly from the current Fastener Express product records for SKUs HF25-175, HF3-175, HF3M-175 and HF3WG-175. Board-thickness suitability, board-profile compatibility and coverage are project-dependent and are not specified in the product records — verify them with the decking manufacturer.
Frequently Asked Questions
What is the difference between HF3 and HF3M?
Both are 3" 304 stainless fasteners in 175-count boxes. HF3 sets a 1/8" board gap; HF3M sets a 3/16" gap. Choose based on the spacing your decking requires.
What does HF3WG mean?
HF3WG is the wide-gap model — a 3" fastener that sets a 1/4" board gap, sold in 175-count boxes.
How many fasteners are in a box?
Each HIDfast fastener box contains 175 collated fasteners, confirmed in the product record specs.
Which fastener do I need for grooved boards?
It depends on board thickness and the required gap. Pre-grooved boards also require the HIDfast grooved-board attachment. Confirm the board profile before ordering.
Are HIDfast fasteners stainless steel?
Yes. All four current models are 304 stainless steel, per the product records.
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