hammer

A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal (as with a forge), or to crush rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, warfare, and percussive musicianship (as with a gong).
Hammering is use of a hammer in its strike capacity, as opposed to prying with an secondary claw or grappling with a secondary hook. Carpentry and blacksmithing hammers are generally wielded from a stationary stance against a stationary target as gripped and propelled with one arm, in a lengthy downward planar arc—downward to add kinetic energy to the impact—pivoting mainly around the shoulder and elbow, with a small but brisk wrist rotation shortly before impact; for extreme impact, concurrent motions of the torso and knee can lower the shoulder joint during the swing to further increase the length of the swing arc (but this is tiring). War hammers are often wielded in non-vertical planes of motion, with a far greater share of energy input provided from the legs and hips, which can also include a lunging motion, especially against moving targets. Small mallets can be swung from the wrists in a smaller motion permitting a much higher cadence of repeated strikes. Use of hammers and heavy mallets for demolition must adapt the hammer stroke to the location and orientation of the target, which can necessitate a clubbing or golfing motion with a two-handed grip.
The modern hammer head is typically made of steel which has been heat treated for hardness, and the handle (also known as a haft or helve) is typically made of wood or plastic.
Ubiquitous in framing, the claw hammer has a "claw" to pull nails out of wood, and is commonly found in an inventory of household tools in North America. Other types of hammer vary in shape, size, and structure, depending on their purposes. Hammers used in many trades include sledgehammers, mallets, and ball-peen hammers. Although most hammers are hand tools, powered hammers, such as steam hammers and trip hammers, are used to deliver forces beyond the capacity of the human arm. There are over 40 different types of hammers that have many different types of uses.For hand hammers, the grip of the shaft is an important consideration. Many forms of hammering by hand are heavy work, and perspiration can lead to slippage from the hand, turning a hammer into a dangerous or destructive uncontrolled projectile. Steel is highly elastic and transmits shock and vibration; steel is also a good conductor of heat, making it unsuitable for contact with bare skin in frigid conditions. Modern hammers with steel shafts are almost invariably clad with a synthetic polymer to improve grip, dampen vibration, and to provide thermal insulation. A suitably contoured handle is also an important aid in providing a secure grip during heavy use. Traditional wooden handles were reasonably good in all regards, but lack strength and durability compared to steel, and there are safety issues with wooden handles if the head becomes loose on the shaft.
The high elasticity of the steel head is important in energy transfer, especially when used in conjunction with an equally elastic anvil.
In terms of human physiology, many uses of the hammer involve coordinated ballistic movements under intense muscular forces which must be planned in advance at the neuromuscular level, as they occur too rapidly for conscious adjustment in flight. For this reason, accurate striking at speed requires more practice than a tapping movement to the same target area. It has been suggested that the cognitive demands for pre-planning, sequencing and accurate timing associated with the related ballistic movements of throwing, clubbing, and hammering precipitated aspects of brain evolution in early hominids.

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  1. M

    Water hammer advice?? (I’ve checked old posts)

    Hi all. Just had a neighbour knock the door regarding a water hammer issue. My own house developed this issue sometime last year as well which is when the neighbours roughly started. Severn Trent were doing bits and bobs out in the street back then but this is probably a coincidence. Our water...
  2. J

    Why do I hear a hammer related noise coming from my water pipes?

    This issue arose about a year ago. Does anyone have an idea why I occasionally hear (about once every hour or longer) a hammer related noise coming from my copper water pipes when no water is being used? It basically sounds like the noise you hear after the water shuts off when your toilet bowl...
  3. Q

    Is it normal for PVC water pipes to Hammer?

    Hi I've got water hammer issues with my cold feed and some with the hot feed. When the cold sink tap, cold bath tap and thermostatic shower in the main bathroom is opened and closed there are hammering sounds from the living room ceiling. It sounds like knocking. There's no hammering whilst...
  4. C

    Water Hammer after new bathroom installed

    Hi I've recently had a new bathroom installed. I've noticed when I flush the downstairs loo there was a hammer type noise under the bathroom floor when the cold feed for the loo turned off/ same with the washing machine. So I turned off the mains water supply. Opened the highest tap first...
  5. M

    Bad case of water hammer.

    Hi everyone I have been a plumber for 3 years now, I haven't come across many issues with water hammer so I'm not to sure what to do. it happens on the hot pipework, more specifically the hot taps in the bathroom (basin and bath). but it only seems to happen when I open the hot tap to a...
  6. R

    Unsolvable water hammer when shutting taps

    I have read a few threads including one by Debbie Stano that were similar to my issue but that thread stopped a while back without any resolution I could see. I'm in Brisbane, Australia but I'm after general ideas from anyone here or in UK (I realise this is a UK based site). Point form...
  7. M

    Water hammer at same time every night

    I wonder can anyone give me some advice over what has become a very annoying situation? Approximately three months ago, what I assume to be water hammer started in the airing cupboard of my second floor flat. This manifested, and continues to do so, as a repeated, i.e. every 60 seconds or so...
  8. J

    Water Hammer - after pipe change

    Had two pipes changed - one cold and one hot. The cold had a leak and the warm was punctured and about to leak so both were replaced - about 50cm sections in each pipe. After that I started getting water hammer - banging of pipes. I've tried lowering the water pressure - that helps a bit but...
  9. T

    Pipe Hammer Increasing

    Recent hammer started to get violent. 30yr old extension retained galvanised pipe riser to 1st floor and an unvented hot water cylnder installed (no header tank). No problems until last 9 months or so when pipes began to hammer on turn on/off taps/cistern (grnd and/or 1st). Recently this has...
  10. L

    New Bathroom Mixer Taps are creating a Water Hammer Issue

    We are renovating our upstairs bathrooms and there is an issue with shutting off the new mixer fittings - all six of them. The matter is holding up progress though it seems no one knows what to do. We built our home about 28 years ago. The only mixer we installed was in the kitchen, all the...
  11. T

    Water Hammer problem

    We have had a minor water hammer issue for years but it was never really a problem until the last year or so. It is so loud it sometimes make you jump, it's driving us crackers. It happens sometimes when we use the electric shower or washing machine but then it's not at it's worse. It never...
  12. Robcrick88

    Can you get water hammer when stopcock is off?

    Been getting water hammer everytime neighbour turns off their taps. Very loud in our house and have asked neighbour who denies hearing anything. I tried turning off my stopcock and switching off boiler for a few hours and could still hear the banging when they use their taps. Is it possible to...
  13. Chrisbarber

    Water hammer moved from washer to toilet flushing

    We recently, about 2 days ago, started getting water hammer from using the washing machine, this has been fixed by attaching an arrestor to the inlet hose which great. However we've now started getting it from the toilet completing a flush, which is upstairs and not near the washer. Is it normal...
  14. D

    House pressure reducing valve cold water hammer

    Having issues with water hammer, I have a megaflo with balanced hot / cold using a heat stadia 3 bar prv, this seems ok as getting 3 bar at taps with test gauge, the outside tap is between the house incoming stop valve and the 3 bar PRV and that is showing just over 4.5 bar. If I switch a hot...
  15. O

    Do new tap cartridges fix water hammer?

    Hi all, We have some terrible water hammer in our house. I've had a plumber come round to try and fix it, to no avail, but I'm not convinced he chose the right course of action. He started by checking the water pressure, securing a few pipes in the roof space which was fair enough, but...
  16. D

    Water Hammer following Combi boiler installation

    Worcester Bosch Greenstar i combi installed. Since installation water hammer happens when hot taps are turned off, but only when the heating is on. Have you experienced the sam?
  17. D

    Water Hammer on washing Machine

    Have a problem with water hammer on washing machine, solved it for a bit with a mini rester been thro 2 seem to only last a year or so and expensive. So purchased a 1/2" T and a 0.16L mini expansion vessel and T what pressure should it be set at? When I first used machine it seemed ok then few...
  18. J

    Quooker water hammer

    Greetings and Merry Xmas to all Just been to an interesting callout. Quooker fusion pro3 tap recently fitted in a new kitchen on a small 2 bed mid terrace with a Ideal logic 30 combi. Customer getting the most horrendous water hammer, started the day after the "plumbers" left for xmas...
  19. M

    water hammer after flushing toilet

    Hi, I have been having water hammer after flushing toilet in the past couple of weeks. I have tried turning off the stopcock and opened all taps to drain all the water in pipes and toilet. The water hummer then fixed for a few flushes but it comes back. It's ok a few weeks ago before we fixed...
  20. M

    Water hammer ceramic disc taps

    Can you get water hammer from ceramic discs on tap valves? Have been to a job where is it sounds like its coming from there. But I know this isn't always the case. Thanks
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