Figure 25: Optimizing the trim shear conditions or polishing a flat trimmed edge approaches what is achievable with laser trimming and water jet cutting. Data from dome testing of DP 350Y/600T. S-53 Quality - If you’re caring for your garden, then you expect the best quality from your pruning shears. With high-quality, durable, and rust-resistant steel, the best pruning shears make the whole production so much more straightforward. Instead of struggling against stubborn sap, poor grip, and uncomfortable design, high-quality shears guarantee you’ll be able to keep your garden looking fresh and blooming every time. In areas where it is essential to reduce grout loss to a minimum, the addition of tape at all butt joints and side laps may offer an economical solution, it should be noted that this is not standard practice and must be discussed at pre-tender stage. Advanced High-Strength Steels (AHSS) exhibit high degrees of work hardening, resulting in improved forming capabilities compared to conventional HSLA steels. However, the same high work hardening creates higher strength and hardness in sheared or punched edges, leading to reduced edge ductility. Microstructural features in some AHSS grades contribute to their sheared edge performance. While laser cutting results in less edge damage than mechanical cutting methods, the heat from laser cutting produces a localized hear treatment, changing the strength and hardness at the edge. Achieving the best formability for chosen processing path requires generating a consistent good quality edge from the cutting operation. The higher loads required to shear AHSS with increasingly higher tensile strength creates additional deflection of dies and processing equipment. This deflection may alter clearances measured under a static condition once the die, press, or slitting equipment is placed under load. As a large percentage of presses, levelers, straighteners, blankers, and slitting equipment were designed years ago, the significantly higher loads required to process today’s AHSS may exceed equipment beyond their design limits, dramatically altering their performance.

Size and Weight - Sort of related to comfort but important enough to warrant its own little section, the size and weight is essential for finding the right shears to suit you. You want to find lightweight shears which will allow you to reach up high - as is a common requirement in pruning - and not feel exhausted after finishing just one plant. Specification: Warranty: yes (2 years) , Power: 7.2V , Run Time: 60 minutes ,Charge Time: 3-5 hours Figure 8: Burr height comparison for mild steel and two AHSS grades as a function of the number of hits. Results for DP 500Y800T and Mart 1150Y1400T are identical and shown as the AHSS curve. C-2

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Handrails are fixed to the underside on the beam, ensuring the top of flange free from obstructions. System must be installed PRIOR to Netting. Practitioners in the field typically do not cut perpendicular to the sheet surface – angled punches and blades are known to reduce cutting forces. For example, long shear blades might have a 2 to 3 degree angle on them to minimize peak tonnages. There are additional benefits to altering the punch profile and impacting angle. Using a narrow flat file (or saw file), follow the angle of the blade and sharpen the edge with long, strokes. It may be worth using a vice to keep the shears totally secure, but it's entirely up to you! Evergreen Yew hedges make one of the most forgiving when it comes to maintenance. When pruned correctly yew creates one of the best barriers and evergreen screens. To avoid unexpected problems during a program launch, use production intent tooling as early in the development as possible. This may be a challenge since blanking dies are usually among the last set of tools completed. In the interim, many companies choose to use laser cut blanks. Tool, blank, and process development must account for the lower-ductility sheared edges in production blanks.

a form of deformation or fracture in which parallel planes in a body or assembly slide over one another This article describes the impact of cutting and cut-edge quality on edge ductility. The primary tests which quantify edge ductility are Hole Expansion Testing , 2-D Edge Tension Testing , and Half Specimen Dome Testing . These links detail the testing procedures. The Hole Expansion Testing article has additional information pertaining to the effect of burr orientation and punch shape. Putting shear angles into cutting tools is a well-known approach to reduce cutting forces. Modifying the cutting tool leads to other benefits in terms of edge ductility. Researchers studied the effects of a beveled punch instead of the traditional flat bottom punch. S-9, S-50 , S-52 In these studies, the optimized bevel angle was between 3 and 6 degrees, the shear direction was parallel the rolling direction of the coil with a die clearance of 17%. With the optimal cutting parameters, the hole expansion ratio increased by 60% when compared to conventional flat punching process. As expected, a reduction in the maximum shearing force occurred – by more than 50% in certain conditions. Dropping the shearing force helps reduce the snap through reverse tonnage, leading to longer tool and press life .Where supports are to receive shear studs, top flanges must be unpainted and free from grease or rust that might adversely affect the weld. Refer to Fixings Section 4.6 for guidance on minimum bearings.

The Manual Handling Operations Regulations 1992 place a legal responsibility on employers to ensure that any manual handling operations are eliminated, so far as is reasonably practicable. However, the handle isn’t the most ergonomic and is a little difficult to balance compared to the NETTA trimmer, so prolonged use on your hedges or bushes could get a little uncomfortable after a while. On top of this, the blades aren’t as easy to change as it first appears, but you get the hang of it after a while. Since you’ll have gloves on anyway the ergonomic aspect isn’t too important, but combined with the weight, it is slightly noticeable. Burr height increases with tool wear and increasing die clearances for shearing mild steel, but AHSS tends to maintain a constant burr height. This means extended intervals between tool sharpening may be possible with AHSS parts, providing edge quality and edge performance remain acceptable. Edge preparation methods like milling, laser trimming, and water-jet cutting minimize cold working at the edges, resulting in the greatest edge ductility, Testing of mild steel resulted in the expected performance where burr height increases continuously with tool wear and clearance, making burr height a reasonable indicator of when to sharpen punching or cutting tools. However, for the AHSS grades studied, burr height did not increase with more hits. It is possible that the relatively lower ductility AHSS grades are not capable of reaching greater burr height due to fracturing, where the more formable mild steel continues to generate ever-increasing burr height with more hits and increasing tool wear.Multi-angle replaceable double-sided base plate suitable for left- and right-handed usage. Spare base plates. Whilst fall protection during work activities is generally well planned & organised it is often the access to the level of work that causes the most significant hazard.

Clearances for punching, blanking, and shearing should increase as the strength of the material increases, but only up to a point. At the highest strengths, reducing clearance improves tool chipping risk. If you are struggling with having this disease or the caterpillar we have an article on the best box replacement hedges. Final Word from Me Figure 16: Effect of hole punching clearance on hole expansion of Complex Phase steel grade CP1200. U-3 Figure 1: Cross Section of a Punched Hole Showing the Shear Face Components and Shear Affected Zone. K-10 With summer fully underway, it’s time to get in the garden, enjoy the sun and start pruning those overgrown hedges, or bothersome trees that have grown a little too long in the leaf.Figure 17: Cutting clearance affects hole expansion performance in DP780 from six global suppliers. K-56 You don’t need to go out into your garden and measure each branch to make your decision, you probably know a general size already, so if you’re unsure, remember the wider the diameter the more branches you can trim away with ease.